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Perfect number

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2473: 1711: 5077: 2468:{\displaystyle {\begin{alignedat}{3}6&=2^{1}(2^{2}-1)&&=1+2+3,\\28&=2^{2}(2^{3}-1)&&=1+2+3+4+5+6+7\\&&&=1^{3}+3^{3}\\496&=2^{4}(2^{5}-1)&&=1+2+3+\cdots +29+30+31\\&&&=1^{3}+3^{3}+5^{3}+7^{3}\\8128&=2^{6}(2^{7}-1)&&=1+2+3+\cdots +125+126+127\\&&&=1^{3}+3^{3}+5^{3}+7^{3}+9^{3}+11^{3}+13^{3}+15^{3}\\33550336&=2^{12}(2^{13}-1)&&=1+2+3+\cdots +8189+8190+8191\\&&&=1^{3}+3^{3}+5^{3}+\cdots +123^{3}+125^{3}+127^{3}\end{alignedat}}} 38: 7763: 3272: 10024: 2907: 964: 1367:= 2, 3, 5, 7, 13, 17, 19, 31, 61, 89, 107, 127, 521, 607, 1279, 2203, 2281, 3217, 4253, 4423, 9689, 9941, 11213, 19937, 21701, 23209, 44497, 86243, 110503, 132049, 216091, 756839, 859433, 1257787, 1398269, 2976221, 3021377, 6972593, 13466917, 20996011, 24036583, 25964951, 30402457, 32582657, 37156667, 42643801, 43112609 and 57885161 (sequence 461:(1194–1252) mentioned the next three perfect numbers (33,550,336; 8,589,869,056; and 137,438,691,328) and listed a few more which are now known to be incorrect. The first known European mention of the fifth perfect number is a manuscript written between 1456 and 1461 by an unknown mathematician. In 1588, the Italian mathematician 5582:, Chapter 16, he says of perfect numbers, "There is a method of producing them, neat and unfailing, which neither passes by any of the perfect numbers nor fails to differentiate any of those that are not such, which is carried out in the following way." He then goes on to explain a procedure which is equivalent to finding a 4749: 664: 3267:{\displaystyle {\begin{array}{rcl}6_{10}=&2^{2}+2^{1}&=110_{2}\\28_{10}=&2^{4}+2^{3}+2^{2}&=11100_{2}\\496_{10}=&2^{8}+2^{7}+2^{6}+2^{5}+2^{4}&=111110000_{2}\\8128_{10}=&\!\!2^{12}+2^{11}+2^{10}+2^{9}+2^{8}+2^{7}+2^{6}\!\!&=1111111000000_{2}\end{array}}} 5279:
is a natural number that is equal to the sum of all or some of its proper divisors. A semiperfect number that is equal to the sum of all its proper divisors is a perfect number. Most abundant numbers are also semiperfect; abundant numbers which are not semiperfect are called
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All even perfect numbers have a very precise form; odd perfect numbers either do not exist or are rare. There are a number of results on perfect numbers that are actually quite easy to prove but nevertheless superficially impressive; some of them also come under
4576: 2632: 3881: 959:{\displaystyle {\begin{aligned}p=2&:\quad 2^{1}(2^{2}-1)=2\times 3=6\\p=3&:\quad 2^{2}(2^{3}-1)=4\times 7=28\\p=5&:\quad 2^{4}(2^{5}-1)=16\times 31=496\\p=7&:\quad 2^{6}(2^{7}-1)=64\times 127=8128.\end{aligned}}} 3319:
stated that Euclid's rule gives all perfect numbers, thus implying that no odd perfect number exists, but Euler himself stated: "Whether ... there are any odd perfect numbers is a most difficult question". More recently,
4473:... a prolonged meditation on the subject has satisfied me that the existence of any one such —its escape, so to say, from the complex web of conditions which hem it in on all sides—would be little short of a miracle. 3967: 3606: 61:, that is, divisors excluding the number itself. For instance, 6 has proper divisors 1, 2 and 3, and 1 + 2 + 3 = 6, so 6 is a perfect number. The next perfect number is 28, since 1 + 2 + 4 + 7 + 14 = 28. 445:
in his first-century book "On the creation" mentions perfect numbers, claiming that the world was created in 6 days and the moon orbits in 28 days because 6 and 28 are perfect. Philo is followed by
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itself has to be prime. He also says (wrongly) that the perfect numbers end in 6 or 8 alternately. (The first 5 perfect numbers end with digits 6, 8, 6, 8, 6; but the sixth also ends in 6.)
1231:(Alhazen) circa AD 1000 was unwilling to go that far, declaring instead (also without proof) that the formula yielded only every even perfect number. It was not until the 18th century that 4856: 1385:= 74207281, 77232917, and 82589933. Although it is still possible there may be others within this range, initial but exhaustive tests by GIMPS have revealed no other perfect numbers for 3766: 2692:
It follows that by adding the digits of any even perfect number (except 6), then adding the digits of the resulting number, and repeating this process until a single digit (called the
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identified the sixth (8,589,869,056) and the seventh (137,438,691,328) perfect numbers, and also proved that every perfect number obtained from Euclid's rule ends with a 6 or an 8.
4744:{\displaystyle {\frac {1}{6}}+{\frac {1}{3}}+{\frac {1}{2}}+{\frac {1}{1}}={\frac {1}{6}}+{\frac {2}{6}}+{\frac {3}{6}}+{\frac {6}{6}}={\frac {1+2+3+6}{6}}={\frac {2\cdot 6}{6}}=2} 2480: 1614: 1704: 1658: 457:(Book XI, Chapter 30) in the early 5th century AD, repeating the claim that God created the world in 6 days because 6 is the smallest perfect number. The Egyptian mathematician 8126: 4564: 4392: 3687: 2889: 651: 130: 4940: 2824: 2761: 1457: 1358: 1288: 1192: 551: 402: 5266: 5047: 87:, so a perfect number is one that is equal to its aliquot sum. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors; in symbols, 6868: 5010: 3492: 3416: 3452: 453:, who adds the observation that there are only four perfect numbers that are less than 10,000. (Commentary on Genesis 1. 14–19). St Augustine defines perfect numbers in 157: 3332:, and it has been conjectured as well that there are no odd harmonic divisor numbers other than 1. Many of the properties proved about odd perfect numbers also apply to 337:
In about 300 BC Euclid showed that if 2 âˆ’ 1 is prime then 2(2 âˆ’ 1) is perfect. The first four perfect numbers were the only ones known to early
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between even perfect numbers and Mersenne primes; each Mersenne prime generates one even perfect number, and vice versa. This result is often referred to as the
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Every even perfect number ends in 6 or 28, base ten; and, with the only exception of 6, ends in 1 in base 9. Therefore, in particular the
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below 109332539. As of December 2018, 51 Mersenne primes are known, and therefore 51 even perfect numbers (the largest of which is
3522: 8921: 8936: 8916: 3316: 7752: 7558: 7402: 7229: 5741: 5714: 5667: 5578: 9629: 9209: 7949: 7762: 5133: 6264: 6167: 3336:, and Pace Nielsen has suggested that sufficient study of those numbers may lead to a proof that no odd perfect numbers exist. 8931: 5787: 9715: 4229: 7699: 7593: 4887:. There are only three types of non-trapezoidal numbers: even perfect numbers, powers of two, and the numbers of the form 4089:{\displaystyle {\frac {1}{q}}+{\frac {1}{p_{1}}}+{\frac {1}{p_{2}}}+\cdots +{\frac {1}{p_{k}}}>{\frac {\ln k}{2\ln 2}}} 9031: 9381: 8700: 8493: 2660:(after subtracting 1 from the perfect number and dividing the result by 9) ending in 3 or 5, the sequence starting with 9416: 9386: 9061: 9051: 7903: 6027:
KĂŒhnel, Ullrich (1950). "VerschĂ€rfung der notwendigen Bedingungen fĂŒr die Existenz von ungeraden vollkommenen Zahlen".
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The Collected Mathematical Papers of James Joseph Sylvester p. 590, tr. from "Sur les nombres dits de Hamilton",
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Steuerwald, R. "VerschĂ€rfung einer notwendigen Bedingung fĂŒr die Existenz einer ungeraden vollkommenen Zahl".
7397:. Chapman & Hall/CRC Pure and Applied Mathematics. Vol. 201. CRC Press. Problem 7.4.11, p. 428. 4871: 4397: 329:
It is not known whether there are any odd perfect numbers, nor whether infinitely many perfect numbers exist.
5552: 9745: 9710: 9496: 9406: 9280: 9255: 9164: 9154: 8766: 8748: 8668: 8078: 7944: 7868: 7020: 6866:(1950). "Satze uber Kreisteilungspolynome und ihre Anwendungen auf einige zahlentheoretisehe Probleme. II". 5323: 5308: 5120: 3329: 37: 1575: 10005: 9275: 9149: 8780: 8556: 8336: 8263: 7929: 7888: 6217:
Zelinsky, Joshua (July 2019). "Upper bounds on the second largest prime factor of an odd perfect number".
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has at least 101 prime factors and at least 10 distinct prime factors. If 3 is not one of the factors of
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It is unknown whether any odd perfect numbers exist, though various results have been obtained. In 1496,
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gives various other kinds of numbers. Numbers where the sum is less than the number itself are called
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with a power of two in a similar way to the construction of even perfect numbers from Mersenne primes.
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noted 8128 as early as around AD 100. In modern language, Nicomachus states without proof that
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Riele, H.J.J. "Perfect Numbers and Aliquot Sequences" in H.W. Lenstra and R. Tijdeman (eds.):
7398: 7392: 7225: 7126: 7073: 6989: 6940: 6885: 6837: 6788: 6721: 6001: 5851: 5781: 5737: 5731: 5710: 5704: 5663: 5583: 5425: 5050: 4884: 3277: 2627:{\displaystyle T_{2^{p}-1}=1+{\frac {(2^{p}-2)\times (2^{p}+1)}{2}}=1+9\times T_{(2^{p}-2)/3}} 1499: 450: 338: 198: 7375: 7219: 5687: 5345: 4948: 1538: 1505: 1197: 1098: 1053: 1016: 971: 556: 407: 264: 9957: 9750: 9336: 9308: 9298: 9290: 9174: 9139: 9134: 9101: 8795: 8758: 8649: 8644: 8639: 8629: 8601: 8488: 8440: 8435: 8392: 8331: 8083: 8058: 7978: 7964: 7898: 7782: 7742: 7564: 7542: 7505: 7446: 7332: 7297: 7254: 7197: 7118: 6979: 6877: 6827: 6778: 6713: 6572: 6506: 6424: 6363: 6287: 6236: 6190: 6148: 6112: 6036: 6009: 5991: 5879: 5536: 5269: 5241: 5205: 5181: 5169: 5160: 3333: 3284: 1569: 54: 7085: 7001: 6952: 6897: 6849: 6800: 6733: 9933: 9822: 9755: 9681: 9604: 9578: 9396: 9109: 8966: 8901: 8871: 8861: 8856: 8522: 8430: 8377: 8221: 8161: 8068: 8063: 7988: 7982: 7919: 7817: 7807: 7737: 7568: 7081: 6997: 6948: 6893: 6845: 6796: 6729: 6013: 5930: 5201: 5197: 5185: 5089: 6704:
McDaniel, Wayne L. (1970). "The non-existence of odd perfect numbers of a certain form".
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28 is also the only even perfect number that is a sum of two positive cubes of integers (
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Yamada, Tomohiro (2019). "A new upper bound for odd perfect numbers of a special form".
6420: 6283: 6186: 6108: 6089: 4883:; that is, they cannot be represented as the difference of two positive non-consecutive 3328:
suggesting that indeed no odd perfect number should exist. All perfect numbers are also
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associated with a perfect number is a constant sequence. All perfect numbers are also
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The number of divisors of a perfect number (whether even or odd) must be even, because
4484: 3321: 1232: 1228: 1006: 1002: 462: 319: 315: 297: 241: 7684: 6984: 6967: 5390:, and both 23 and 89 yield a remainder of 1 when divided by 22. Furthermore, whenever 2912: 10042: 9861: 9845: 9786: 9740: 9436: 9421: 9331: 9056: 8614: 8483: 8445: 8402: 8283: 8268: 8258: 8216: 8206: 8181: 8022: 7822: 7812: 7792: 7543: 7458: 7371: 7344: 7309: 7274: 7138: 6905: 6741: 6048: 5875: 5683: 5532: 5080: 3876:{\displaystyle \alpha +2e_{1}+2e_{2}+2e_{3}+\cdots +2e_{k}\geq {\frac {99k-224}{37}}} 1010: 77: 46: 7650: 6783: 6761: 6577: 6558: 6368: 6248: 6139:
Konyagin, Sergei; Acquaah, Peter (2012). "On Prime Factors of Odd Perfect Numbers".
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distributed computing project has shown that the first 48 even perfect numbers are
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Nankar, M.L.: "History of perfect numbers," Ganita Bharati 1, no. 1–2 (1979), 7–8.
6428: 6315: 6292: 6195: 6117: 5520:"A proof that all even perfect numbers are a power of two times a Mersenne prime" 5196:. A pair of numbers which are the sum of each other's proper divisors are called 9856: 9731: 9536: 9000: 8891: 8846: 8841: 8591: 8498: 8397: 8226: 8201: 8176: 7666: 6923: 6594:"On inequalities involving counts of the prime factors of an odd perfect number" 6593: 6461: 6168:"The second largest prime divisor of an odd perfect number exceeds ten thousand" 259: 84: 69: 6348: 1381:
Three higher perfect numbers have also been discovered, namely those for which
9993: 9974: 9270: 8881: 7670: 7017:"Some results concerning the non-existence of odd perfect numbers of the form 6881: 6832: 6815: 6511: 6494: 6391: 6265:"The third largest prime divisor of an odd perfect number exceeds one hundred" 6240: 6152: 5760: 5193: 1132: 458: 342: 65: 8104: 7450: 7323:
Kanold, HJ (1956). "Eine Bemerkung šuber die Menge der vollkommenen zahlen".
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is not a prime number. In fact, Mersenne primes are very rare: of the primes
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A projected distributed computing project to search for odd perfect numbers.
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proved that all even perfect numbers are of this form. This is known as the
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Jones, Chris; Lord, Nick (1999). "Characterising non-trapezoidal numbers".
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Commentary on the Gospel of John 28.1.1–4, with further references in the
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must be smaller than an effectively computable constant depending only on
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Kanold, H.-J. (1941). "Untersuchungen ĂŒber ungerade vollkommene Zahlen".
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The Reception of Philonic Arithmological Exegesis in Didymus the Blind's
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For example, the first four perfect numbers are generated by the formula
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must add up to 2 (to get this, take the definition of a perfect number,
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perfect numbers, nor whether there are infinitely many Mersenne primes.
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The Development of Arabic Mathematics: Between Arithmetic and Algebra
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The second largest prime factor is greater than 10, and is less than
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Hornfeck, B (1955). "Zur Dichte der Menge der vollkommenen zahlen".
7258: 4218:) =  (1, ..., 1, 2, ..., 2) with 7433:
for a translation and discussion of this proposition and its proof.
7113: 6613: 6231: 3962:{\displaystyle qp_{1}p_{2}p_{3}\cdots p_{k}<2N^{\frac {17}{26}}} 8003: 6314:
Bibby, Sean; Vyncke, Pieter; Zelinsky, Joshua (23 November 2021).
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From these two results it follows that every perfect number is an
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The third largest prime factor is greater than 100, and less than
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Society of Biblical Literature National Meeting, Atlanta, Georgia
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Furthermore, several minor results are known about the exponents
3601:{\displaystyle N=q^{\alpha }p_{1}^{2e_{1}}\cdots p_{k}^{2e_{k}},} 5736:. Washington: Mathematical Association of America. p. 132. 5706:
Wonders of Numbers: Adventures in Mathematics, Mind, and Meaning
5639:(Dordrecht: Kluwer Academic Publishers, 1994), pp. 328–329. 9991: 9955: 9919: 9883: 9843: 9468: 9357: 9083: 8998: 8953: 8830: 8520: 8467: 8419: 8353: 8305: 8243: 8147: 8108: 7688: 6462:"On the Total Number of Prime Factors of an Odd Perfect Number" 6392:"Odd perfect numbers have at least nine distinct prime factors" 7601: 7394:
Number Theory: An Introduction to Pure and Applied Mathematics
6968:"A new result concerning the structure of odd perfect numbers" 6349:"Odd perfect numbers, Diophantine equations, and upper bounds" 5944:"Mathematicians Open a New Front on an Ancient Number Problem" 7380:. Washington: Carnegie Institution of Washington. p. 25. 6316:"On the Third Largest Prime Divisor of an Odd Perfect Number" 5692:. Washington: Carnegie Institution of Washington. p. 10. 174: 7644: 6917: 6915: 5884:. Washington: Carnegie Institution of Washington. p. 6. 5541:. Washington: Carnegie Institution of Washington. p. 4. 5253: 1572:. Furthermore, each even perfect number except for 6 is the 7633: 6924:"Extensions of some results concerning odd perfect numbers" 6760:
Fletcher, S. Adam; Nielsen, Pace P.; Ochem, Pascal (2012).
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every even perfect number is represented in binary form as
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will yield all the even perfect numbers. Thus, there is a
6559:"On the number of prime factors of an odd perfect number" 5733:
Mathematical Treks: From Surreal Numbers to Magic Circles
4310:) ≠ (1, ..., 1, 3), (1, ..., 1, 5), (1, ..., 1, 6). 41:
Illustration of the perfect number status of the number 6
7492:"A Lower Bound for the set of odd Perfect Prime Numbers" 6820:
Journal of the Australian Mathematical Society, Series A
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Suryanarayana, D. (1963). "On Odd Perfect Numbers II".
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is prime (though he stated this somewhat differently),
6090:"Odd perfect numbers have a prime factor exceeding 10" 4284:{\displaystyle (t-1)/4\leq u\leq 2t+{\sqrt {\alpha }}} 1580: 1502:(and hence equal to the sum of the integers from 1 to 1050:
itself be prime. However, not all numbers of the form
7224:, John Wiley & Sons, Section 2.3, Exercise 2(6), 7023: 5428: 5348: 5250: 5022: 4991: 4951: 4893: 4760: 4579: 4527: 4400: 4349: 4232: 3977: 3891: 3775: 3703: 3657: 3525: 3463: 3426: 3387: 2910: 2839: 2777: 2714: 2483: 1714: 1666: 1626: 1578: 1541: 1508: 1465: 1410: 1311: 1241: 1200: 1145: 1101: 1056: 1019: 974: 667: 601: 559: 504: 410: 355: 300: 267: 244: 201: 138: 93: 83:
The sum of proper divisors of a number is called its
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Prime Numbers and Computer Methods for Factorisation
6495:"Improved upper bounds for odd multiperfect numbers" 9815: 9769: 9729: 9680: 9654: 9587: 9571: 9550: 9517: 9482: 9322: 9289: 9246: 9223: 9100: 8788: 8779: 8757: 8714: 8676: 8667: 8600: 8542: 8533: 8046: 8002: 7963: 7912: 7846: 7770: 7720: 7221:
Computational Number Theory and Modern Cryptography
6816:"On the largest component of an odd perfect number" 5755: 5753: 7165:Makowski, A. (1962). "Remark on perfect numbers". 7049: 5450: 5367: 5260: 5041: 5004: 4970: 4934: 4850: 4743: 4558: 4451: 4386: 4283: 4088: 3961: 3875: 3760: 3681: 3600: 3486: 3446: 3410: 3266: 2883: 2818: 2755: 2626: 2467: 1698: 1652: 1608: 1560: 1527: 1490: 1451: 1352: 1282: 1219: 1186: 1120: 1075: 1038: 993: 958: 645: 578: 545: 429: 396: 306: 286: 250: 230: 166:This definition is ancient, appearing as early as 151: 124: 3244: 3243: 3154: 3153: 6972:Proceedings of the American Mathematical Society 6687:Proceedings of the American Mathematical Society 6666:Cohen, Graeme (1978). "On odd perfect numbers". 6455: 6453: 5709:. Oxford: Oxford University Press. p. 360. 2477:Even perfect numbers (except 6) are of the form 57:that is equal to the sum of its positive proper 7439:Journal fĂŒr die Reine und Angewandte Mathematik 7186:"On a remark of Makowski about perfect numbers" 6869:Journal fĂŒr die reine und angewandte Mathematik 6499:Bulletin of the Australian Mathematical Society 5060:of every even perfect number other than 6 is 1. 4471: 27:Integer equal to the sum of its proper divisors 7530:, Vol. 154, Amsterdam, 1982, pp. 141–157. 7253:(497). The Mathematical Association: 262–263. 8120: 7700: 7015:McDaniel, Wayne L.; Hagis, Peter Jr. (1975). 6966:Hagis, Peter Jr.; McDaniel, Wayne L. (1972). 4187:+1 have a prime factor in a given finite set 195:also proved a formation rule (IX.36) whereby 8: 7634:sequence A000396 (Perfect numbers) 5304:List of Mersenne primes and perfect numbers 5184:, and where it is greater than the number, 4851:{\displaystyle 1/28+1/14+1/7+1/4+1/2+1/1=2} 9988: 9952: 9916: 9880: 9840: 9514: 9479: 9465: 9354: 9097: 9080: 8995: 8950: 8827: 8785: 8673: 8539: 8530: 8517: 8464: 8421:Possessing a specific set of other numbers 8416: 8350: 8302: 8240: 8144: 8127: 8113: 8105: 7707: 7693: 7685: 7541:SĂĄndor, Jozsef; Crstici, Borislav (2004). 5463:= 11, 23, 83, 131, 179, 191, 239, 251, ... 5200:, and larger cycles of numbers are called 3761:{\displaystyle N<2^{(4^{k+1}-2^{k+1})}} 3691:At least one of the prime powers dividing 486:Are there infinitely many perfect numbers? 7509: 7201: 7112: 7038: 7028: 7022: 6983: 6831: 6782: 6612: 6576: 6510: 6410: 6367: 6291: 6230: 6194: 6116: 5995: 5975:"Odd perfect numbers are greater than 10" 5433: 5427: 5353: 5347: 5252: 5251: 5249: 5029: 5021: 4995: 4990: 4956: 4950: 4917: 4898: 4892: 4834: 4820: 4806: 4792: 4778: 4764: 4759: 4717: 4684: 4671: 4658: 4645: 4632: 4619: 4606: 4593: 4580: 4578: 4532: 4526: 4495:The only even perfect number of the form 4424: 4416: 4411: 4399: 4363: 4348: 4274: 4248: 4231: 4057: 4046: 4037: 4020: 4011: 4000: 3991: 3978: 3976: 3948: 3932: 3919: 3909: 3899: 3890: 3852: 3843: 3821: 3805: 3789: 3774: 3741: 3722: 3714: 3702: 3658: 3656: 3587: 3579: 3574: 3559: 3551: 3546: 3536: 3524: 3474: 3464: 3462: 3437: 3427: 3425: 3398: 3388: 3386: 3254: 3237: 3224: 3211: 3198: 3185: 3172: 3159: 3142: 3128: 3113: 3100: 3087: 3074: 3061: 3046: 3032: 3017: 3004: 2991: 2976: 2962: 2947: 2934: 2919: 2911: 2909: 2863: 2844: 2838: 2801: 2782: 2776: 2738: 2719: 2713: 2614: 2599: 2591: 2551: 2526: 2516: 2493: 2488: 2482: 2455: 2442: 2429: 2410: 2397: 2384: 2306: 2293: 2269: 2256: 2243: 2230: 2217: 2204: 2191: 2178: 2100: 2087: 2063: 2050: 2037: 2024: 1946: 1933: 1909: 1896: 1818: 1805: 1746: 1733: 1715: 1713: 1671: 1665: 1631: 1625: 1587: 1579: 1577: 1546: 1540: 1513: 1507: 1473: 1464: 1434: 1415: 1409: 1335: 1316: 1310: 1265: 1246: 1240: 1205: 1199: 1169: 1150: 1144: 1106: 1100: 1061: 1055: 1024: 1018: 979: 973: 919: 906: 848: 835: 777: 764: 706: 693: 668: 666: 625: 606: 600: 564: 558: 528: 509: 503: 415: 409: 379: 360: 354: 299: 272: 266: 243: 220: 200: 143: 137: 98: 92: 7377:History of the Theory of Numbers, Vol. I 6528:"An upper bound for odd perfect numbers" 5896:"The oldest open problem in mathematics" 5881:History of the Theory of Numbers, Vol. I 5689:History of the Theory of Numbers, Vol. I 5538:History of the Theory of Numbers, Vol. I 4981:The number of perfect numbers less than 4507: 4500: 4452:{\displaystyle N<2^{4^{2e^{2}+8e+3}}} 2826:for odd integer (not necessarily prime) 7549:. Dordrecht: Kluwer Academic. pp.  7153:Compte Rendu de l'Association Française 6762:"Sieve methods for odd perfect numbers" 6635:Pomerance, Carl; Luca, Florian (2010). 5812:MacTutor History of Mathematics Archive 5487: 5335: 4341:cannot be 3, 5, 24, 6, 8, 11, 14 or 18. 3507:has at least 12 distinct prime factors. 3343:must satisfy the following conditions: 3310:(more unsolved problems in mathematics) 1660:odd cubes (odd cubes up to the cube of 490:(more unsolved problems in mathematics) 7602:Perfect, amicable and sociable numbers 7528:Computational Methods in Number Theory 7050:{\displaystyle p^{\alpha }M^{2\beta }} 6922:Cohen, G. L.; Williams, R. J. (1985). 6219:International Journal of Number Theory 6141:International Journal of Number Theory 6064:"On the Form of an Odd Perfect Number" 5779: 4171:5), then the smallest prime factor of 2708:. This works with all perfect numbers 2636:with each resulting triangular number 437:is prime. He seems to be unaware that 5211:By definition, a perfect number is a 3288: 1620:and is equal to the sum of the first 1609:{\displaystyle {\tfrac {2^{p}+1}{3}}} 1005:, after the seventeenth-century monk 7: 7645:Great Internet Mersenne Prime Search 7607:Perfect numbers – History and Theory 6637:"On the radical of a perfect number" 6592:Graeme Clayton, Cody Hansen (2023). 6557:Ochem, Pascal; Rao, MichaĂ«l (2014). 6493:Chen, Yong-Gao; Tang, Cui-E (2014). 5973:Ochem, Pascal; Rao, MichaĂ«l (2012). 5766:Great Internet Mersenne Prime Search 5016:> 0 is a constant. In fact it is 4517:of the divisors of a perfect number 4191:, then the smallest prime factor of 3283:Every even perfect number is also a 3276:Thus every even perfect number is a 1699:{\displaystyle 2^{\frac {p+1}{2}}-1} 7715:Divisibility-based sets of integers 5414:is congruent to 1 or 7 mod 8, then 553:is an even perfect number whenever 238:is an even perfect number whenever 64:The first four perfect numbers are 10059:Unsolved problems in number theory 6460:Zelinsky, Joshua (3 August 2021). 5942:Nadis, Steve (10 September 2020). 3306:Are there any odd perfect numbers? 1653:{\displaystyle 2^{\frac {p-1}{2}}} 1459:, each even perfect number is the 1046:to be prime, it is necessary that 25: 7753:Fundamental theorem of arithmetic 6985:10.1090/S0002-9939-1972-0292740-5 5807:"Abu Ali al-Hasan ibn al-Haytham" 5659:History of Mathematics: Volume II 4879:The even perfect numbers are not 4559:{\displaystyle \sigma _{1}(n)=2n} 4387:{\displaystyle k\leq 2e^{2}+8e+2} 3682:{\displaystyle {\frac {k-1}{2}}.} 3381:is greater than 10 and less than 2884:{\displaystyle 2^{p-1}(2^{p}-1),} 1139:perfect numbers were of the form 646:{\displaystyle 2^{p-1}(2^{p}-1),} 125:{\displaystyle \sigma _{1}(n)=2n} 10022: 9630:Perfect digit-to-digit invariant 7761: 4935:{\displaystyle 2^{n-1}(2^{n}+1)} 3634:are distinct odd primes (Euler). 2819:{\displaystyle 2^{m-1}(2^{m}-1)} 2756:{\displaystyle 2^{p-1}(2^{p}-1)} 1452:{\displaystyle 2^{p-1}(2^{p}-1)} 1353:{\displaystyle 2^{p-1}(2^{p}-1)} 1283:{\displaystyle 2^{p-1}(2^{p}-1)} 1187:{\displaystyle 2^{n-1}(2^{n}-1)} 1135:had stated (without proof) that 546:{\displaystyle 2^{p-1}(2^{p}-1)} 397:{\displaystyle 2^{n-1}(2^{n}-1)} 7429:, Book IX, Proposition 36. See 6784:10.1090/S0025-5718-2011-02576-7 6641:New York Journal of Mathematics 6578:10.1090/S0025-5718-2013-02776-7 6369:10.1090/S0025-5718-2015-02941-X 6071:Australian Mathematical Gazette 5997:10.1090/S0025-5718-2012-02563-4 5662:. New York: Dover. p. 21. 3301:Unsolved problem in mathematics 1393:with 49,724,095 digits). It is 901: 830: 759: 688: 481:Unsolved problem in mathematics 7361:Texeira J. VIII (1886), 11–16. 7155:(Toulouse, 1887), pp. 164–168. 5261:{\displaystyle {\mathcal {S}}} 5042:{\displaystyle o({\sqrt {n}})} 5036: 5026: 4929: 4910: 4544: 4538: 4245: 4233: 3753: 3715: 2875: 2856: 2813: 2794: 2750: 2731: 2611: 2592: 2563: 2544: 2538: 2519: 2318: 2299: 2112: 2093: 1958: 1939: 1830: 1811: 1758: 1739: 1485: 1466: 1446: 1427: 1347: 1328: 1277: 1258: 1181: 1162: 1128:is prime for only 48 of them. 931: 912: 860: 841: 789: 770: 718: 699: 637: 618: 540: 521: 391: 372: 349:perfect number is of the form 217: 205: 110: 104: 1: 8469:Expressible via specific sums 7359:Note sur les nombres parfaits 6429:10.1090/S0025-5718-07-01990-4 6293:10.1090/S0025-5718-99-01127-8 6196:10.1090/S0025-5718-99-01126-6 6118:10.1090/S0025-5718-08-02050-9 5188:. These terms, together with 3647:The smallest prime factor of 7545:Handbook of number theory II 5005:{\displaystyle c{\sqrt {n}}} 4867:cannot be a perfect square. 3487:{\displaystyle {\sqrt{2N}}.} 3411:{\displaystyle {\sqrt{3N}}.} 3377:The largest prime factor of 1301:An exhaustive search by the 173:(VII.22) where it is called 9558:Multiplicative digital root 7589:Encyclopedia of Mathematics 5649:Bayerische Staatsbibliothek 5557:www-groups.dcs.st-and.ac.uk 5217:restricted divisor function 4942:formed as the product of a 4566:, and divide both sides by 4489:strong law of small numbers 4175:must lie between 10 and 10. 3447:{\displaystyle {\sqrt{2N}}} 1404:As well as having the form 152:{\displaystyle \sigma _{1}} 10085: 7497:Mathematics of Computation 7184:Gallardo, Luis H. (2010). 6770:Mathematics of Computation 6564:Mathematics of Computation 6399:Mathematics of Computation 6356:Mathematics of Computation 6272:Mathematics of Computation 6175:Mathematics of Computation 6097:Mathematics of Computation 5983:Mathematics of Computation 5786:: CS1 maint: url-status ( 5609:Rogers, Justin M. (2015). 5586:based on a Mersenne prime. 5579:Introduction to Arithmetic 968:Prime numbers of the form 472: 175: 29: 10018: 10001: 9987: 9965: 9951: 9929: 9915: 9893: 9879: 9852: 9839: 9635:Perfect digital invariant 9478: 9464: 9372: 9353: 9210:Superior highly composite 9096: 9079: 9007: 8994: 8962: 8949: 8837: 8826: 8529: 8516: 8474: 8463: 8426: 8415: 8363: 8349: 8312: 8301: 8254: 8239: 8157: 8143: 7950:Superior highly composite 7759: 6882:10.1515/crll.1950.188.129 6833:10.1017/S1446788700028251 6526:Nielsen, Pace P. (2003). 6512:10.1017/S0004972713000488 6390:Nielsen, Pace P. (2007). 6347:Nielsen, Pace P. (2015). 6241:10.1142/S1793042119500659 6153:10.1142/S1793042112500935 6088:Goto, T; Ohno, Y (2008). 6029:Mathematische Zeitschrift 5761:"GIMPS Milestones Report" 5599:edition: vol. 385, 58–61. 5134:superior highly composite 1618:centered nonagonal number 1491:{\displaystyle (2^{p}-1)} 1292:one-to-one correspondence 1013:and perfect numbers. For 9248:Euler's totient function 9032:Euler–Jacobi pseudoprime 8307:Other polynomial numbers 7847:Constrained divisor sums 7451:10.1515/crll.1941.183.98 7247:The Mathematical Gazette 5817:University of St Andrews 5451:{\displaystyle 2^{p}-1,} 5192:itself, come from Greek 4178:More generally, if all 2 3356:is not divisible by 105. 3330:harmonic divisor numbers 1235:proved that the formula 1087:are prime; for example, 341:, and the mathematician 231:{\displaystyle q(q+1)/2} 161:sum-of-divisors function 9062:Somer–Lucas pseudoprime 9052:Lucas–Carmichael number 8887:Lazy caterer's sequence 7659:"8128: Perfect Numbers" 7653:, math forum at Drexel. 7468:S.-B. Bayer. Akad. Wiss 7101:Colloquium Mathematicum 5368:{\displaystyle 2^{p}-1} 5324:Harmonic divisor number 5309:Multiply perfect number 4971:{\displaystyle 2^{n}+1} 3339:Any odd perfect number 1561:{\displaystyle 2^{p-1}} 1528:{\displaystyle 2^{p}-1} 1220:{\displaystyle 2^{n}-1} 1121:{\displaystyle 2^{p}-1} 1076:{\displaystyle 2^{p}-1} 1039:{\displaystyle 2^{p}-1} 994:{\displaystyle 2^{p}-1} 579:{\displaystyle 2^{p}-1} 430:{\displaystyle 2^{n}-1} 318:. Two millennia later, 287:{\displaystyle 2^{p}-1} 30:For the 2012 film, see 8937:Wedderburn–Etherington 8337:Lucky numbers of Euler 7051: 5458:which is the case for 5452: 5388:2 − 1 = 2047 = 23 × 89 5369: 5319:Unitary perfect number 5262: 5173: 5083:of numbers under 100: 5043: 5006: 4972: 4936: 4852: 4745: 4560: 4499: + 1 is 28 ( 4475: 4453: 4388: 4285: 4090: 3963: 3877: 3762: 3683: 3602: 3488: 3448: 3412: 3268: 2885: 2820: 2757: 2628: 2469: 1700: 1654: 1610: 1562: 1529: 1492: 1453: 1354: 1284: 1221: 1188: 1122: 1089:2 − 1 = 2047 = 23 × 89 1077: 1040: 995: 960: 647: 580: 547: 431: 398: 314:—what is now called a 308: 288: 252: 232: 153: 126: 42: 9225:Prime omega functions 9042:Frobenius pseudoprime 8832:Combinatorial numbers 8701:Centered dodecahedral 8494:Primary pseudoperfect 7728:Integer factorization 7391:Redmond, Don (1996). 7218:Yan, Song Y. (2012), 7123:10.4064/cm7339-3-2018 7052: 6814:Cohen, G. L. (1987). 6706:Archiv der Mathematik 6263:Iannucci, DE (2000). 6166:Iannucci, DE (1999). 5614:Commentary on Genesis 5453: 5370: 5268:-perfect numbers, or 5263: 5079: 5044: 5007: 4973: 4937: 4872:Ore's harmonic number 4853: 4746: 4561: 4454: 4389: 4286: 4091: 3964: 3878: 3763: 3684: 3603: 3489: 3449: 3413: 3269: 2886: 2833:Owing to their form, 2821: 2758: 2629: 2470: 1701: 1655: 1611: 1563: 1530: 1493: 1454: 1355: 1285: 1222: 1189: 1123: 1078: 1041: 996: 961: 648: 581: 548: 432: 399: 309: 294:for positive integer 289: 253: 233: 154: 127: 40: 32:Perfect Number (film) 9684:-composition related 9484:Arithmetic functions 9086:Arithmetic functions 9022:Elliptic pseudoprime 8706:Centered icosahedral 8686:Centered tetrahedral 7431:D.E. Joyce's website 7021: 6864:Kanold, Hans-Joachim 5803:Robertson, Edmund F. 5730:Peterson, I (2002). 5703:Pickover, C (2001). 5426: 5422:will be a factor of 5396:Sophie Germain prime 5346: 5314:Superperfect numbers 5248: 5067:perfect number is 6. 5020: 4989: 4949: 4891: 4758: 4577: 4525: 4398: 4347: 4230: 3975: 3889: 3773: 3701: 3655: 3523: 3461: 3424: 3385: 2908: 2902:zeros; for example: 2837: 2775: 2771:numbers of the form 2712: 2481: 1712: 1664: 1624: 1576: 1539: 1506: 1463: 1408: 1309: 1296:Euclid–Euler theorem 1239: 1198: 1143: 1099: 1054: 1017: 972: 665: 599: 557: 502: 475:Euclid–Euler theorem 469:Even perfect numbers 408: 353: 324:Euclid–Euler theorem 298: 265: 242: 199: 136: 91: 9610:Kaprekar's constant 9130:Colossally abundant 9017:Catalan pseudoprime 8917:Schröder–Hipparchus 8696:Centered octahedral 8572:Centered heptagonal 8562:Centered pentagonal 8552:Centered triangular 8152:and related numbers 7940:Colossally abundant 7771:Factorization forms 7537:, Birkhauser, 1985. 7065:Fibonacci Quarterly 6932:Fibonacci Quarterly 6668:Fibonacci Quarterly 6421:2007MaCom..76.2109N 6284:2000MaCom..69..867I 6187:1999MaCom..68.1749I 6109:2008MaCom..77.1859G 6062:Roberts, T (2008). 5801:O'Connor, John J.; 5597:Sources ChrĂ©tiennes 5294:Hyperperfect number 5130:Colossally abundant 4881:trapezoidal numbers 3640:≡ Î± ≡ 1 ( 3594: 3566: 3370:≡ 117 (mod 468) or 3295:Odd perfect numbers 2767:and, in fact, with 443:Philo of Alexandria 10028:Mathematics portal 9970:Aronson's sequence 9716:Smarandache–Wellin 9473:-dependent numbers 9180:Primitive abundant 9067:Strong pseudoprime 9057:Perrin pseudoprime 9037:Fermat pseudoprime 8977:Wolstenholme prime 8801:Squared triangular 8587:Centered decagonal 8582:Centered nonagonal 8577:Centered octagonal 8567:Centered hexagonal 7925:Primitive abundant 7913:With many divisors 7614:Weisstein, Eric W. 7490:Hagis, P. (1973). 7337:10.1007/BF01350108 7302:10.1007/BF01901120 7047: 6777:(279): 1753?1776. 6718:10.1007/BF01220877 6571:(289): 2435–2439. 6405:(260): 2109–2126. 6362:(295): 2549–2567. 6181:(228): 1749–1760. 6103:(263): 1859–1868. 6041:10.1007/BF02230691 5990:(279): 1869–1877. 5929:2006-12-29 at the 5852:Weisstein, Eric W. 5654:David Eugene Smith 5448: 5406:is also prime—and 5365: 5277:semiperfect number 5258: 5174: 5099:Primitive abundant 5039: 5002: 4968: 4932: 4885:triangular numbers 4848: 4741: 4556: 4449: 4384: 4281: 4086: 3959: 3873: 3758: 3679: 3598: 3570: 3542: 3484: 3444: 3408: 3326:heuristic argument 3264: 3262: 2881: 2816: 2753: 2698:8 + 1 + 2 + 8 = 19 2624: 2465: 2463: 1696: 1650: 1606: 1604: 1558: 1525: 1488: 1449: 1397:whether there are 1350: 1280: 1217: 1184: 1118: 1095:up to 68,874,199, 1073: 1036: 991: 956: 954: 643: 576: 543: 427: 394: 304: 284: 248: 228: 149: 122: 43: 10054:Integer sequences 10036: 10035: 10014: 10013: 9983: 9982: 9947: 9946: 9911: 9910: 9875: 9874: 9835: 9834: 9831: 9830: 9650: 9649: 9460: 9459: 9349: 9348: 9345: 9344: 9291:Aliquot sequences 9102:Divisor functions 9075: 9074: 9047:Lucas pseudoprime 9027:Euler pseudoprime 9012:Carmichael number 8990: 8989: 8945: 8944: 8822: 8821: 8818: 8817: 8814: 8813: 8775: 8774: 8663: 8662: 8620:Square triangular 8512: 8511: 8459: 8458: 8411: 8410: 8345: 8344: 8297: 8296: 8235: 8234: 8102: 8101: 5651:, Clm 14908. See 5584:triangular number 5553:"Perfect numbers" 5518:Caldwell, Chris, 5375:are congruent to 5270:Granville numbers 5051:little-o notation 5034: 5000: 4733: 4712: 4679: 4666: 4653: 4640: 4627: 4614: 4601: 4588: 4301:, ...,  4279: 4209:, ...,  4109:, ...,  4084: 4052: 4026: 4006: 3986: 3956: 3871: 3674: 3625:, ...,  3479: 3442: 3403: 3334:Descartes numbers 3278:pernicious number 2895:ones followed by 2570: 1687: 1647: 1603: 1500:triangular number 459:Ismail ibn FallĆ«s 451:Didymus the Blind 339:Greek mathematics 307:{\displaystyle p} 251:{\displaystyle q} 16:(Redirected from 10076: 10049:Divisor function 10026: 9989: 9958:Natural language 9953: 9917: 9885:Generated via a 9881: 9841: 9746:Digit-reassembly 9711:Self-descriptive 9515: 9480: 9466: 9417:Lucas–Carmichael 9407:Harmonic divisor 9355: 9281:Sparsely totient 9256:Highly cototient 9165:Multiply perfect 9155:Highly composite 9098: 9081: 8996: 8951: 8932:Telephone number 8828: 8786: 8767:Square pyramidal 8749:Stella octangula 8674: 8540: 8531: 8523:Figurate numbers 8518: 8465: 8417: 8351: 8303: 8241: 8145: 8129: 8122: 8115: 8106: 8079:Harmonic divisor 7965:Aliquot sequence 7945:Highly composite 7869:Multiply perfect 7765: 7743:Divisor function 7709: 7702: 7695: 7686: 7681: 7679: 7678: 7669:. Archived from 7632: 7627: 7626: 7617:"Perfect Number" 7597: 7584:"Perfect number" 7572: 7548: 7523: 7513: 7504:(124): 951–953. 7475: 7462: 7410: 7408: 7388: 7382: 7381: 7368: 7362: 7355: 7349: 7348: 7320: 7314: 7313: 7285: 7279: 7278: 7242: 7236: 7234: 7215: 7209: 7207: 7205: 7181: 7175: 7174: 7162: 7156: 7149: 7143: 7142: 7116: 7096: 7090: 7089: 7061: 7056: 7054: 7053: 7048: 7046: 7045: 7033: 7032: 7012: 7006: 7005: 6987: 6963: 6957: 6956: 6928: 6919: 6910: 6909: 6860: 6854: 6853: 6835: 6811: 6805: 6804: 6786: 6766: 6757: 6746: 6745: 6701: 6695: 6694: 6682: 6676: 6675: 6663: 6657: 6656: 6654: 6652: 6632: 6626: 6625: 6623: 6621: 6616: 6598: 6589: 6583: 6582: 6580: 6554: 6548: 6547: 6545: 6543: 6523: 6517: 6516: 6514: 6490: 6484: 6483: 6481: 6479: 6466: 6457: 6448: 6447: 6445: 6443: 6414: 6396: 6387: 6381: 6380: 6378: 6376: 6371: 6353: 6344: 6338: 6337: 6335: 6333: 6320: 6311: 6305: 6304: 6302: 6300: 6295: 6278:(230): 867–879. 6269: 6260: 6254: 6252: 6234: 6225:(6): 1183–1189. 6214: 6208: 6207: 6205: 6203: 6198: 6172: 6163: 6157: 6156: 6147:(6): 1537–1540. 6136: 6130: 6129: 6127: 6125: 6120: 6094: 6085: 6079: 6078: 6068: 6059: 6053: 6052: 6024: 6018: 6017: 5999: 5979: 5970: 5959: 5958: 5956: 5954: 5939: 5933: 5920: 5914: 5913: 5911: 5909: 5900: 5892: 5886: 5885: 5872: 5866: 5865: 5864: 5855:"Perfect Number" 5847: 5841: 5840: 5838: 5837: 5826: 5820: 5819: 5798: 5792: 5791: 5785: 5777: 5775: 5773: 5757: 5748: 5747: 5727: 5721: 5720: 5700: 5694: 5693: 5680: 5674: 5673: 5646: 5640: 5633: 5627: 5626: 5620: 5606: 5600: 5593: 5587: 5574: 5568: 5567: 5565: 5563: 5549: 5543: 5542: 5529: 5523: 5516: 5510: 5509: 5507: 5506: 5496:"A000396 - OEIS" 5492: 5475: 5473: 5464: 5462: 5457: 5455: 5454: 5449: 5438: 5437: 5421: 5413: 5405: 5393: 5389: 5385: 5374: 5372: 5371: 5366: 5358: 5357: 5340: 5267: 5265: 5264: 5259: 5257: 5256: 5242:aliquot sequence 5239: 5206:practical number 5167: 5158: 5149: 5140: 5127: 5121:highly composite 5114: 5105: 5096: 5087: 5072:Related concepts 5048: 5046: 5045: 5040: 5035: 5030: 5011: 5009: 5008: 5003: 5001: 4996: 4977: 4975: 4974: 4969: 4961: 4960: 4941: 4939: 4938: 4933: 4922: 4921: 4909: 4908: 4857: 4855: 4854: 4849: 4838: 4824: 4810: 4796: 4782: 4768: 4754:For 28, we have 4750: 4748: 4747: 4742: 4734: 4729: 4718: 4713: 4708: 4685: 4680: 4672: 4667: 4659: 4654: 4646: 4641: 4633: 4628: 4620: 4615: 4607: 4602: 4594: 4589: 4581: 4565: 4563: 4562: 4557: 4537: 4536: 4458: 4456: 4455: 4450: 4448: 4447: 4446: 4445: 4429: 4428: 4393: 4391: 4390: 4385: 4368: 4367: 4334: 4290: 4288: 4287: 4282: 4280: 4275: 4252: 4163: â‰Ą 1 ( 4147: â‰Ą 2 ( 4131: â‰Ą 1 ( 4095: 4093: 4092: 4087: 4085: 4083: 4069: 4058: 4053: 4051: 4050: 4038: 4027: 4025: 4024: 4012: 4007: 4005: 4004: 3992: 3987: 3979: 3968: 3966: 3965: 3960: 3958: 3957: 3949: 3937: 3936: 3924: 3923: 3914: 3913: 3904: 3903: 3882: 3880: 3879: 3874: 3872: 3867: 3853: 3848: 3847: 3826: 3825: 3810: 3809: 3794: 3793: 3767: 3765: 3764: 3759: 3757: 3756: 3752: 3751: 3733: 3732: 3688: 3686: 3685: 3680: 3675: 3670: 3659: 3607: 3605: 3604: 3599: 3593: 3592: 3591: 3578: 3565: 3564: 3563: 3550: 3541: 3540: 3493: 3491: 3490: 3485: 3480: 3478: 3473: 3465: 3453: 3451: 3450: 3445: 3443: 3441: 3436: 3428: 3417: 3415: 3414: 3409: 3404: 3402: 3397: 3389: 3366:≡ 1 (mod 12) or 3324:has presented a 3302: 3289:Related concepts 3285:practical number 3273: 3271: 3270: 3265: 3263: 3259: 3258: 3242: 3241: 3229: 3228: 3216: 3215: 3203: 3202: 3190: 3189: 3177: 3176: 3164: 3163: 3147: 3146: 3133: 3132: 3118: 3117: 3105: 3104: 3092: 3091: 3079: 3078: 3066: 3065: 3051: 3050: 3037: 3036: 3022: 3021: 3009: 3008: 2996: 2995: 2981: 2980: 2967: 2966: 2952: 2951: 2939: 2938: 2924: 2923: 2901: 2894: 2890: 2888: 2887: 2882: 2868: 2867: 2855: 2854: 2829: 2825: 2823: 2822: 2817: 2806: 2805: 2793: 2792: 2766: 2762: 2760: 2759: 2754: 2743: 2742: 2730: 2729: 2707: 2703: 2699: 2691: 2683: 2675: 2667: 2659: 2651: 2643: 2633: 2631: 2630: 2625: 2623: 2622: 2618: 2604: 2603: 2571: 2566: 2556: 2555: 2531: 2530: 2517: 2506: 2505: 2498: 2497: 2474: 2472: 2471: 2466: 2464: 2460: 2459: 2447: 2446: 2434: 2433: 2415: 2414: 2402: 2401: 2389: 2388: 2373: 2372: 2371: 2322: 2311: 2310: 2298: 2297: 2274: 2273: 2261: 2260: 2248: 2247: 2235: 2234: 2222: 2221: 2209: 2208: 2196: 2195: 2183: 2182: 2167: 2166: 2165: 2116: 2105: 2104: 2092: 2091: 2068: 2067: 2055: 2054: 2042: 2041: 2029: 2028: 2013: 2012: 2011: 1962: 1951: 1950: 1938: 1937: 1914: 1913: 1901: 1900: 1885: 1884: 1883: 1834: 1823: 1822: 1810: 1809: 1762: 1751: 1750: 1738: 1737: 1705: 1703: 1702: 1697: 1689: 1688: 1683: 1672: 1659: 1657: 1656: 1651: 1649: 1648: 1643: 1632: 1615: 1613: 1612: 1607: 1605: 1599: 1592: 1591: 1581: 1570:hexagonal number 1567: 1565: 1564: 1559: 1557: 1556: 1534: 1532: 1531: 1526: 1518: 1517: 1497: 1495: 1494: 1489: 1478: 1477: 1458: 1456: 1455: 1450: 1439: 1438: 1426: 1425: 1392: 1388: 1384: 1372: 1366: 1359: 1357: 1356: 1351: 1340: 1339: 1327: 1326: 1289: 1287: 1286: 1281: 1270: 1269: 1257: 1256: 1226: 1224: 1223: 1218: 1210: 1209: 1193: 1191: 1190: 1185: 1174: 1173: 1161: 1160: 1127: 1125: 1124: 1119: 1111: 1110: 1094: 1090: 1086: 1082: 1080: 1079: 1074: 1066: 1065: 1049: 1045: 1043: 1042: 1037: 1029: 1028: 1000: 998: 997: 992: 984: 983: 965: 963: 962: 957: 955: 924: 923: 911: 910: 853: 852: 840: 839: 782: 781: 769: 768: 711: 710: 698: 697: 656: 652: 650: 649: 644: 630: 629: 617: 616: 592:, Prop. IX.36). 585: 583: 582: 577: 569: 568: 552: 550: 549: 544: 533: 532: 520: 519: 482: 440: 436: 434: 433: 428: 420: 419: 403: 401: 400: 395: 384: 383: 371: 370: 313: 311: 310: 305: 293: 291: 290: 285: 277: 276: 257: 255: 254: 249: 237: 235: 234: 229: 224: 178: 177: 158: 156: 155: 150: 148: 147: 131: 129: 128: 123: 103: 102: 55:positive integer 21: 10084: 10083: 10079: 10078: 10077: 10075: 10074: 10073: 10069:Perfect numbers 10064:Mersenne primes 10039: 10038: 10037: 10032: 10010: 10006:Strobogrammatic 9997: 9979: 9961: 9943: 9925: 9907: 9889: 9871: 9848: 9827: 9811: 9770:Divisor-related 9765: 9725: 9676: 9646: 9583: 9567: 9546: 9513: 9486: 9474: 9456: 9368: 9367:related numbers 9341: 9318: 9285: 9276:Perfect totient 9242: 9219: 9150:Highly abundant 9092: 9071: 9003: 8986: 8958: 8941: 8927:Stirling second 8833: 8810: 8771: 8753: 8710: 8659: 8596: 8557:Centered square 8525: 8508: 8470: 8455: 8422: 8407: 8359: 8358:defined numbers 8341: 8308: 8293: 8264:Double Mersenne 8250: 8231: 8153: 8139: 8137:natural numbers 8133: 8103: 8098: 8042: 7998: 7959: 7930:Highly abundant 7908: 7889:Unitary perfect 7842: 7766: 7757: 7738:Unitary divisor 7716: 7713: 7676: 7674: 7657:Grimes, James. 7656: 7651:Perfect Numbers 7612: 7611: 7582: 7579: 7561: 7540: 7511:10.2307/2005530 7489: 7483: 7481:Further reading 7478: 7465: 7445:(183): 98–109. 7436: 7419: 7414: 7413: 7405: 7390: 7389: 7385: 7370: 7369: 7365: 7356: 7352: 7322: 7321: 7317: 7287: 7286: 7282: 7259:10.2307/3619053 7244: 7243: 7239: 7232: 7217: 7216: 7212: 7183: 7182: 7178: 7164: 7163: 7159: 7150: 7146: 7098: 7097: 7093: 7059: 7034: 7024: 7019: 7018: 7014: 7013: 7009: 6965: 6964: 6960: 6926: 6921: 6920: 6913: 6862: 6861: 6857: 6813: 6812: 6808: 6764: 6759: 6758: 6749: 6703: 6702: 6698: 6684: 6683: 6679: 6665: 6664: 6660: 6650: 6648: 6634: 6633: 6629: 6619: 6617: 6596: 6591: 6590: 6586: 6556: 6555: 6551: 6541: 6539: 6525: 6524: 6520: 6492: 6491: 6487: 6477: 6475: 6464: 6459: 6458: 6451: 6441: 6439: 6394: 6389: 6388: 6384: 6374: 6372: 6351: 6346: 6345: 6341: 6331: 6329: 6318: 6313: 6312: 6308: 6298: 6296: 6267: 6262: 6261: 6257: 6216: 6215: 6211: 6201: 6199: 6170: 6165: 6164: 6160: 6138: 6137: 6133: 6123: 6121: 6092: 6087: 6086: 6082: 6066: 6061: 6060: 6056: 6026: 6025: 6021: 5977: 5972: 5971: 5962: 5952: 5950: 5948:Quanta Magazine 5941: 5940: 5936: 5931:Wayback Machine 5921: 5917: 5907: 5905: 5898: 5894: 5893: 5889: 5874: 5873: 5869: 5850: 5849: 5848: 5844: 5835: 5833: 5828: 5827: 5823: 5800: 5799: 5795: 5778: 5771: 5769: 5759: 5758: 5751: 5744: 5729: 5728: 5724: 5717: 5702: 5701: 5697: 5682: 5681: 5677: 5670: 5652: 5647: 5643: 5635:Roshdi Rashed, 5634: 5630: 5618: 5608: 5607: 5603: 5594: 5590: 5575: 5571: 5561: 5559: 5551: 5550: 5546: 5531: 5530: 5526: 5517: 5513: 5504: 5502: 5494: 5493: 5489: 5484: 5479: 5478: 5465: 5460: 5459: 5429: 5424: 5423: 5415: 5407: 5399: 5391: 5387: 5386:. For example, 5376: 5349: 5344: 5343: 5342:All factors of 5341: 5337: 5332: 5290: 5246: 5245: 5219: 5178:proper divisors 5172: 5165: 5163: 5156: 5154: 5147: 5145: 5138: 5136: 5125: 5123: 5112: 5110: 5108:Highly abundant 5103: 5101: 5094: 5092: 5085: 5074: 5018: 5017: 4987: 4986: 4952: 4947: 4946: 4913: 4894: 4889: 4888: 4756: 4755: 4719: 4686: 4575: 4574: 4573:For 6, we have 4528: 4523: 4522: 4480: 4420: 4412: 4407: 4396: 4395: 4359: 4345: 4344: 4329: 4320: 4314: 4309: 4300: 4228: 4227: 4217: 4208: 4186: 4162: 4146: 4130: 4117: 4108: 4070: 4059: 4042: 4016: 3996: 3973: 3972: 3944: 3928: 3915: 3905: 3895: 3887: 3886: 3854: 3839: 3817: 3801: 3785: 3771: 3770: 3737: 3718: 3710: 3699: 3698: 3660: 3653: 3652: 3633: 3624: 3583: 3555: 3532: 3521: 3520: 3466: 3459: 3458: 3429: 3422: 3421: 3390: 3383: 3382: 3374:≡ 81 (mod 324). 3362:is of the form 3317:Jacques LefĂšvre 3313: 3312: 3307: 3304: 3300: 3297: 3261: 3260: 3250: 3245: 3233: 3220: 3207: 3194: 3181: 3168: 3155: 3151: 3138: 3135: 3134: 3124: 3119: 3109: 3096: 3083: 3070: 3057: 3055: 3042: 3039: 3038: 3028: 3023: 3013: 3000: 2987: 2985: 2972: 2969: 2968: 2958: 2953: 2943: 2930: 2928: 2915: 2906: 2905: 2896: 2892: 2859: 2840: 2835: 2834: 2827: 2797: 2778: 2773: 2772: 2764: 2763:with odd prime 2734: 2715: 2710: 2709: 2705: 2701: 2697: 2689: 2685: 2681: 2677: 2673: 2669: 2665: 2661: 2657: 2653: 2649: 2645: 2641: 2637: 2595: 2587: 2547: 2522: 2518: 2489: 2484: 2479: 2478: 2462: 2461: 2451: 2438: 2425: 2406: 2393: 2380: 2369: 2368: 2321: 2302: 2289: 2282: 2276: 2275: 2265: 2252: 2239: 2226: 2213: 2200: 2187: 2174: 2163: 2162: 2115: 2096: 2083: 2076: 2070: 2069: 2059: 2046: 2033: 2020: 2009: 2008: 1961: 1942: 1929: 1922: 1916: 1915: 1905: 1892: 1881: 1880: 1833: 1814: 1801: 1794: 1788: 1787: 1761: 1742: 1729: 1722: 1710: 1709: 1673: 1667: 1662: 1661: 1633: 1627: 1622: 1621: 1583: 1582: 1574: 1573: 1542: 1537: 1536: 1509: 1504: 1503: 1469: 1461: 1460: 1430: 1411: 1406: 1405: 1399:infinitely many 1390: 1386: 1382: 1368: 1364: 1331: 1312: 1307: 1306: 1261: 1242: 1237: 1236: 1201: 1196: 1195: 1165: 1146: 1141: 1140: 1102: 1097: 1096: 1092: 1088: 1084: 1057: 1052: 1051: 1047: 1020: 1015: 1014: 1003:Mersenne primes 975: 970: 969: 953: 952: 915: 902: 894: 882: 881: 844: 831: 823: 811: 810: 773: 760: 752: 740: 739: 702: 689: 681: 663: 662: 654: 621: 602: 597: 596: 560: 555: 554: 524: 505: 500: 499: 493: 492: 487: 484: 480: 477: 471: 438: 411: 406: 405: 375: 356: 351: 350: 335: 296: 295: 268: 263: 262: 240: 239: 197: 196: 189:complete number 176:τέλΔÎčÎżÏ‚ ጀρÎčΞΌός 139: 134: 133: 94: 89: 88: 35: 28: 23: 22: 15: 12: 11: 5: 10082: 10080: 10072: 10071: 10066: 10061: 10056: 10051: 10041: 10040: 10034: 10033: 10031: 10030: 10019: 10016: 10015: 10012: 10011: 10009: 10008: 10002: 9999: 9998: 9992: 9985: 9984: 9981: 9980: 9978: 9977: 9972: 9966: 9963: 9962: 9956: 9949: 9948: 9945: 9944: 9942: 9941: 9939:Sorting number 9936: 9934:Pancake number 9930: 9927: 9926: 9920: 9913: 9912: 9909: 9908: 9906: 9905: 9900: 9894: 9891: 9890: 9884: 9877: 9876: 9873: 9872: 9870: 9869: 9864: 9859: 9853: 9850: 9849: 9846:Binary numbers 9844: 9837: 9836: 9833: 9832: 9829: 9828: 9826: 9825: 9819: 9817: 9813: 9812: 9810: 9809: 9804: 9799: 9794: 9789: 9784: 9779: 9773: 9771: 9767: 9766: 9764: 9763: 9758: 9753: 9748: 9743: 9737: 9735: 9727: 9726: 9724: 9723: 9718: 9713: 9708: 9703: 9698: 9693: 9687: 9685: 9678: 9677: 9675: 9674: 9673: 9672: 9661: 9659: 9656:P-adic numbers 9652: 9651: 9648: 9647: 9645: 9644: 9643: 9642: 9632: 9627: 9622: 9617: 9612: 9607: 9602: 9597: 9591: 9589: 9585: 9584: 9582: 9581: 9575: 9573: 9572:Coding-related 9569: 9568: 9566: 9565: 9560: 9554: 9552: 9548: 9547: 9545: 9544: 9539: 9534: 9529: 9523: 9521: 9512: 9511: 9510: 9509: 9507:Multiplicative 9504: 9493: 9491: 9476: 9475: 9471:Numeral system 9469: 9462: 9461: 9458: 9457: 9455: 9454: 9449: 9444: 9439: 9434: 9429: 9424: 9419: 9414: 9409: 9404: 9399: 9394: 9389: 9384: 9379: 9373: 9370: 9369: 9358: 9351: 9350: 9347: 9346: 9343: 9342: 9340: 9339: 9334: 9328: 9326: 9320: 9319: 9317: 9316: 9311: 9306: 9301: 9295: 9293: 9287: 9286: 9284: 9283: 9278: 9273: 9268: 9263: 9261:Highly totient 9258: 9252: 9250: 9244: 9243: 9241: 9240: 9235: 9229: 9227: 9221: 9220: 9218: 9217: 9212: 9207: 9202: 9197: 9192: 9187: 9182: 9177: 9172: 9167: 9162: 9157: 9152: 9147: 9142: 9137: 9132: 9127: 9122: 9117: 9115:Almost perfect 9112: 9106: 9104: 9094: 9093: 9084: 9077: 9076: 9073: 9072: 9070: 9069: 9064: 9059: 9054: 9049: 9044: 9039: 9034: 9029: 9024: 9019: 9014: 9008: 9005: 9004: 8999: 8992: 8991: 8988: 8987: 8985: 8984: 8979: 8974: 8969: 8963: 8960: 8959: 8954: 8947: 8946: 8943: 8942: 8940: 8939: 8934: 8929: 8924: 8922:Stirling first 8919: 8914: 8909: 8904: 8899: 8894: 8889: 8884: 8879: 8874: 8869: 8864: 8859: 8854: 8849: 8844: 8838: 8835: 8834: 8831: 8824: 8823: 8820: 8819: 8816: 8815: 8812: 8811: 8809: 8808: 8803: 8798: 8792: 8790: 8783: 8777: 8776: 8773: 8772: 8770: 8769: 8763: 8761: 8755: 8754: 8752: 8751: 8746: 8741: 8736: 8731: 8726: 8720: 8718: 8712: 8711: 8709: 8708: 8703: 8698: 8693: 8688: 8682: 8680: 8671: 8665: 8664: 8661: 8660: 8658: 8657: 8652: 8647: 8642: 8637: 8632: 8627: 8622: 8617: 8612: 8606: 8604: 8598: 8597: 8595: 8594: 8589: 8584: 8579: 8574: 8569: 8564: 8559: 8554: 8548: 8546: 8537: 8527: 8526: 8521: 8514: 8513: 8510: 8509: 8507: 8506: 8501: 8496: 8491: 8486: 8481: 8475: 8472: 8471: 8468: 8461: 8460: 8457: 8456: 8454: 8453: 8448: 8443: 8438: 8433: 8427: 8424: 8423: 8420: 8413: 8412: 8409: 8408: 8406: 8405: 8400: 8395: 8390: 8385: 8380: 8375: 8370: 8364: 8361: 8360: 8354: 8347: 8346: 8343: 8342: 8340: 8339: 8334: 8329: 8324: 8319: 8313: 8310: 8309: 8306: 8299: 8298: 8295: 8294: 8292: 8291: 8286: 8281: 8276: 8271: 8266: 8261: 8255: 8252: 8251: 8244: 8237: 8236: 8233: 8232: 8230: 8229: 8224: 8219: 8214: 8209: 8204: 8199: 8194: 8189: 8184: 8179: 8174: 8169: 8164: 8158: 8155: 8154: 8148: 8141: 8140: 8134: 8132: 8131: 8124: 8117: 8109: 8100: 8099: 8097: 8096: 8091: 8086: 8081: 8076: 8071: 8066: 8061: 8056: 8050: 8048: 8044: 8043: 8041: 8040: 8035: 8030: 8025: 8020: 8015: 8009: 8007: 8000: 7999: 7997: 7996: 7991: 7986: 7976: 7970: 7968: 7961: 7960: 7958: 7957: 7952: 7947: 7942: 7937: 7932: 7927: 7922: 7916: 7914: 7910: 7909: 7907: 7906: 7901: 7896: 7891: 7886: 7881: 7876: 7871: 7866: 7861: 7859:Almost perfect 7856: 7850: 7848: 7844: 7843: 7841: 7840: 7835: 7830: 7825: 7820: 7815: 7810: 7805: 7800: 7795: 7790: 7785: 7780: 7774: 7772: 7768: 7767: 7760: 7758: 7756: 7755: 7750: 7745: 7740: 7735: 7730: 7724: 7722: 7718: 7717: 7714: 7712: 7711: 7704: 7697: 7689: 7683: 7682: 7654: 7648: 7642: 7639:OddPerfect.org 7636: 7628: 7609: 7604: 7598: 7578: 7577:External links 7575: 7574: 7573: 7559: 7538: 7531: 7524: 7487: 7482: 7479: 7477: 7476: 7463: 7434: 7420: 7418: 7415: 7412: 7411: 7403: 7383: 7372:Dickson, L. E. 7363: 7350: 7331:(4): 390–392. 7315: 7296:(6): 442–443. 7280: 7237: 7230: 7210: 7203:10.4171/EM/149 7196:(3): 121–126. 7176: 7157: 7144: 7091: 7044: 7041: 7037: 7031: 7027: 7007: 6958: 6911: 6876:(1): 129–146. 6855: 6826:(2): 280–286. 6806: 6747: 6696: 6677: 6658: 6627: 6584: 6549: 6518: 6505:(3): 353–359. 6485: 6449: 6382: 6339: 6306: 6255: 6209: 6158: 6131: 6080: 6054: 6019: 5960: 5934: 5923:Oddperfect.org 5915: 5887: 5876:Dickson, L. E. 5867: 5842: 5832:. Mersenne.org 5821: 5793: 5749: 5742: 5722: 5715: 5695: 5684:Dickson, L. E. 5675: 5668: 5641: 5628: 5601: 5588: 5569: 5544: 5533:Dickson, L. E. 5524: 5511: 5486: 5485: 5483: 5480: 5477: 5476: 5447: 5444: 5441: 5436: 5432: 5364: 5361: 5356: 5352: 5334: 5333: 5331: 5328: 5327: 5326: 5321: 5316: 5311: 5306: 5301: 5299:Leinster group 5296: 5289: 5286: 5255: 5164: 5155: 5146: 5137: 5124: 5111: 5102: 5093: 5084: 5073: 5070: 5069: 5068: 5061: 5054: 5038: 5033: 5028: 5025: 4999: 4994: 4979: 4967: 4964: 4959: 4955: 4931: 4928: 4925: 4920: 4916: 4912: 4907: 4904: 4901: 4897: 4877: 4876: 4875: 4861: 4860: 4859: 4847: 4844: 4841: 4837: 4833: 4830: 4827: 4823: 4819: 4816: 4813: 4809: 4805: 4802: 4799: 4795: 4791: 4788: 4785: 4781: 4777: 4774: 4771: 4767: 4763: 4752: 4740: 4737: 4732: 4728: 4725: 4722: 4716: 4711: 4707: 4704: 4701: 4698: 4695: 4692: 4689: 4683: 4678: 4675: 4670: 4665: 4662: 4657: 4652: 4649: 4644: 4639: 4636: 4631: 4626: 4623: 4618: 4613: 4610: 4605: 4600: 4597: 4592: 4587: 4584: 4555: 4552: 4549: 4546: 4543: 4540: 4535: 4531: 4511: 4504: 4479: 4476: 4463: 4462: 4461: 4460: 4444: 4441: 4438: 4435: 4432: 4427: 4423: 4419: 4415: 4410: 4406: 4403: 4383: 4380: 4377: 4374: 4371: 4366: 4362: 4358: 4355: 4352: 4342: 4325: 4318: 4311: 4305: 4298: 4292: 4278: 4273: 4270: 4267: 4264: 4261: 4258: 4255: 4251: 4247: 4244: 4241: 4238: 4235: 4213: 4206: 4200: 4182: 4176: 4158: 4152: 4142: 4136: 4126: 4113: 4106: 4100: 4099: 4098: 4097: 4082: 4079: 4076: 4073: 4068: 4065: 4062: 4056: 4049: 4045: 4041: 4036: 4033: 4030: 4023: 4019: 4015: 4010: 4003: 3999: 3995: 3990: 3985: 3982: 3970: 3955: 3952: 3947: 3943: 3940: 3935: 3931: 3927: 3922: 3918: 3912: 3908: 3902: 3898: 3894: 3884: 3870: 3866: 3863: 3860: 3857: 3851: 3846: 3842: 3838: 3835: 3832: 3829: 3824: 3820: 3816: 3813: 3808: 3804: 3800: 3797: 3792: 3788: 3784: 3781: 3778: 3768: 3755: 3750: 3747: 3744: 3740: 3736: 3731: 3728: 3725: 3721: 3717: 3713: 3709: 3706: 3696: 3689: 3678: 3673: 3669: 3666: 3663: 3645: 3635: 3629: 3622: 3610: 3609: 3608: 3597: 3590: 3586: 3582: 3577: 3573: 3569: 3562: 3558: 3554: 3549: 3545: 3539: 3535: 3531: 3528: 3515: 3514: 3513:is of the form 3508: 3494: 3483: 3477: 3472: 3469: 3455: 3440: 3435: 3432: 3418: 3407: 3401: 3396: 3393: 3375: 3357: 3351: 3322:Carl Pomerance 3308: 3305: 3299: 3296: 3293: 3257: 3253: 3249: 3246: 3240: 3236: 3232: 3227: 3223: 3219: 3214: 3210: 3206: 3201: 3197: 3193: 3188: 3184: 3180: 3175: 3171: 3167: 3162: 3158: 3152: 3150: 3145: 3141: 3137: 3136: 3131: 3127: 3123: 3120: 3116: 3112: 3108: 3103: 3099: 3095: 3090: 3086: 3082: 3077: 3073: 3069: 3064: 3060: 3056: 3054: 3049: 3045: 3041: 3040: 3035: 3031: 3027: 3024: 3020: 3016: 3012: 3007: 3003: 2999: 2994: 2990: 2986: 2984: 2979: 2975: 2971: 2970: 2965: 2961: 2957: 2954: 2950: 2946: 2942: 2937: 2933: 2929: 2927: 2922: 2918: 2914: 2913: 2880: 2877: 2874: 2871: 2866: 2862: 2858: 2853: 2850: 2847: 2843: 2815: 2812: 2809: 2804: 2800: 2796: 2791: 2788: 2785: 2781: 2770: 2752: 2749: 2746: 2741: 2737: 2733: 2728: 2725: 2722: 2718: 2690:= 3727815, ... 2687: 2679: 2671: 2663: 2655: 2647: 2639: 2621: 2617: 2613: 2610: 2607: 2602: 2598: 2594: 2590: 2586: 2583: 2580: 2577: 2574: 2569: 2565: 2562: 2559: 2554: 2550: 2546: 2543: 2540: 2537: 2534: 2529: 2525: 2521: 2515: 2512: 2509: 2504: 2501: 2496: 2492: 2487: 2458: 2454: 2450: 2445: 2441: 2437: 2432: 2428: 2424: 2421: 2418: 2413: 2409: 2405: 2400: 2396: 2392: 2387: 2383: 2379: 2376: 2374: 2370: 2367: 2364: 2361: 2358: 2355: 2352: 2349: 2346: 2343: 2340: 2337: 2334: 2331: 2328: 2325: 2323: 2320: 2317: 2314: 2309: 2305: 2301: 2296: 2292: 2288: 2285: 2283: 2281: 2278: 2277: 2272: 2268: 2264: 2259: 2255: 2251: 2246: 2242: 2238: 2233: 2229: 2225: 2220: 2216: 2212: 2207: 2203: 2199: 2194: 2190: 2186: 2181: 2177: 2173: 2170: 2168: 2164: 2161: 2158: 2155: 2152: 2149: 2146: 2143: 2140: 2137: 2134: 2131: 2128: 2125: 2122: 2119: 2117: 2114: 2111: 2108: 2103: 2099: 2095: 2090: 2086: 2082: 2079: 2077: 2075: 2072: 2071: 2066: 2062: 2058: 2053: 2049: 2045: 2040: 2036: 2032: 2027: 2023: 2019: 2016: 2014: 2010: 2007: 2004: 2001: 1998: 1995: 1992: 1989: 1986: 1983: 1980: 1977: 1974: 1971: 1968: 1965: 1963: 1960: 1957: 1954: 1949: 1945: 1941: 1936: 1932: 1928: 1925: 1923: 1921: 1918: 1917: 1912: 1908: 1904: 1899: 1895: 1891: 1888: 1886: 1882: 1879: 1876: 1873: 1870: 1867: 1864: 1861: 1858: 1855: 1852: 1849: 1846: 1843: 1840: 1837: 1835: 1832: 1829: 1826: 1821: 1817: 1813: 1808: 1804: 1800: 1797: 1795: 1793: 1790: 1789: 1786: 1783: 1780: 1777: 1774: 1771: 1768: 1765: 1763: 1760: 1757: 1754: 1749: 1745: 1741: 1736: 1732: 1728: 1725: 1723: 1721: 1718: 1717: 1695: 1692: 1686: 1682: 1679: 1676: 1670: 1646: 1642: 1639: 1636: 1630: 1602: 1598: 1595: 1590: 1586: 1555: 1552: 1549: 1545: 1524: 1521: 1516: 1512: 1487: 1484: 1481: 1476: 1472: 1468: 1448: 1445: 1442: 1437: 1433: 1429: 1424: 1421: 1418: 1414: 1379: 1378: 1349: 1346: 1343: 1338: 1334: 1330: 1325: 1322: 1319: 1315: 1279: 1276: 1273: 1268: 1264: 1260: 1255: 1252: 1249: 1245: 1233:Leonhard Euler 1229:Ibn al-Haytham 1216: 1213: 1208: 1204: 1183: 1180: 1177: 1172: 1168: 1164: 1159: 1156: 1153: 1149: 1138: 1117: 1114: 1109: 1105: 1072: 1069: 1064: 1060: 1035: 1032: 1027: 1023: 1009:, who studied 1007:Marin Mersenne 990: 987: 982: 978: 951: 948: 945: 942: 939: 936: 933: 930: 927: 922: 918: 914: 909: 905: 900: 897: 895: 893: 890: 887: 884: 883: 880: 877: 874: 871: 868: 865: 862: 859: 856: 851: 847: 843: 838: 834: 829: 826: 824: 822: 819: 816: 813: 812: 809: 806: 803: 800: 797: 794: 791: 788: 785: 780: 776: 772: 767: 763: 758: 755: 753: 751: 748: 745: 742: 741: 738: 735: 732: 729: 726: 723: 720: 717: 714: 709: 705: 701: 696: 692: 687: 684: 682: 680: 677: 674: 671: 670: 661:, as follows: 642: 639: 636: 633: 628: 624: 620: 615: 612: 609: 605: 575: 572: 567: 563: 542: 539: 536: 531: 527: 523: 518: 515: 512: 508: 488: 485: 479: 470: 467: 463:Pietro Cataldi 426: 423: 418: 414: 393: 390: 387: 382: 378: 374: 369: 366: 363: 359: 348: 334: 331: 320:Leonhard Euler 316:Mersenne prime 303: 283: 280: 275: 271: 247: 227: 223: 219: 216: 213: 210: 207: 204: 146: 142: 121: 118: 115: 112: 109: 106: 101: 97: 51:perfect number 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 10081: 10070: 10067: 10065: 10062: 10060: 10057: 10055: 10052: 10050: 10047: 10046: 10044: 10029: 10025: 10021: 10020: 10017: 10007: 10004: 10003: 10000: 9995: 9990: 9986: 9976: 9973: 9971: 9968: 9967: 9964: 9959: 9954: 9950: 9940: 9937: 9935: 9932: 9931: 9928: 9923: 9918: 9914: 9904: 9901: 9899: 9896: 9895: 9892: 9888: 9882: 9878: 9868: 9865: 9863: 9860: 9858: 9855: 9854: 9851: 9847: 9842: 9838: 9824: 9821: 9820: 9818: 9814: 9808: 9805: 9803: 9800: 9798: 9797:Polydivisible 9795: 9793: 9790: 9788: 9785: 9783: 9780: 9778: 9775: 9774: 9772: 9768: 9762: 9759: 9757: 9754: 9752: 9749: 9747: 9744: 9742: 9739: 9738: 9736: 9733: 9728: 9722: 9719: 9717: 9714: 9712: 9709: 9707: 9704: 9702: 9699: 9697: 9694: 9692: 9689: 9688: 9686: 9683: 9679: 9671: 9668: 9667: 9666: 9663: 9662: 9660: 9657: 9653: 9641: 9638: 9637: 9636: 9633: 9631: 9628: 9626: 9623: 9621: 9618: 9616: 9613: 9611: 9608: 9606: 9603: 9601: 9598: 9596: 9593: 9592: 9590: 9586: 9580: 9577: 9576: 9574: 9570: 9564: 9561: 9559: 9556: 9555: 9553: 9551:Digit product 9549: 9543: 9540: 9538: 9535: 9533: 9530: 9528: 9525: 9524: 9522: 9520: 9516: 9508: 9505: 9503: 9500: 9499: 9498: 9495: 9494: 9492: 9490: 9485: 9481: 9477: 9472: 9467: 9463: 9453: 9450: 9448: 9445: 9443: 9440: 9438: 9435: 9433: 9430: 9428: 9425: 9423: 9420: 9418: 9415: 9413: 9410: 9408: 9405: 9403: 9400: 9398: 9395: 9393: 9390: 9388: 9387:ErdƑs–Nicolas 9385: 9383: 9380: 9378: 9375: 9374: 9371: 9366: 9362: 9356: 9352: 9338: 9335: 9333: 9330: 9329: 9327: 9325: 9321: 9315: 9312: 9310: 9307: 9305: 9302: 9300: 9297: 9296: 9294: 9292: 9288: 9282: 9279: 9277: 9274: 9272: 9269: 9267: 9264: 9262: 9259: 9257: 9254: 9253: 9251: 9249: 9245: 9239: 9236: 9234: 9231: 9230: 9228: 9226: 9222: 9216: 9213: 9211: 9208: 9206: 9205:Superabundant 9203: 9201: 9198: 9196: 9193: 9191: 9188: 9186: 9183: 9181: 9178: 9176: 9173: 9171: 9168: 9166: 9163: 9161: 9158: 9156: 9153: 9151: 9148: 9146: 9143: 9141: 9138: 9136: 9133: 9131: 9128: 9126: 9123: 9121: 9118: 9116: 9113: 9111: 9108: 9107: 9105: 9103: 9099: 9095: 9091: 9087: 9082: 9078: 9068: 9065: 9063: 9060: 9058: 9055: 9053: 9050: 9048: 9045: 9043: 9040: 9038: 9035: 9033: 9030: 9028: 9025: 9023: 9020: 9018: 9015: 9013: 9010: 9009: 9006: 9002: 8997: 8993: 8983: 8980: 8978: 8975: 8973: 8970: 8968: 8965: 8964: 8961: 8957: 8952: 8948: 8938: 8935: 8933: 8930: 8928: 8925: 8923: 8920: 8918: 8915: 8913: 8910: 8908: 8905: 8903: 8900: 8898: 8895: 8893: 8890: 8888: 8885: 8883: 8880: 8878: 8875: 8873: 8870: 8868: 8865: 8863: 8860: 8858: 8855: 8853: 8850: 8848: 8845: 8843: 8840: 8839: 8836: 8829: 8825: 8807: 8804: 8802: 8799: 8797: 8794: 8793: 8791: 8787: 8784: 8782: 8781:4-dimensional 8778: 8768: 8765: 8764: 8762: 8760: 8756: 8750: 8747: 8745: 8742: 8740: 8737: 8735: 8732: 8730: 8727: 8725: 8722: 8721: 8719: 8717: 8713: 8707: 8704: 8702: 8699: 8697: 8694: 8692: 8691:Centered cube 8689: 8687: 8684: 8683: 8681: 8679: 8675: 8672: 8670: 8669:3-dimensional 8666: 8656: 8653: 8651: 8648: 8646: 8643: 8641: 8638: 8636: 8633: 8631: 8628: 8626: 8623: 8621: 8618: 8616: 8613: 8611: 8608: 8607: 8605: 8603: 8599: 8593: 8590: 8588: 8585: 8583: 8580: 8578: 8575: 8573: 8570: 8568: 8565: 8563: 8560: 8558: 8555: 8553: 8550: 8549: 8547: 8545: 8541: 8538: 8536: 8535:2-dimensional 8532: 8528: 8524: 8519: 8515: 8505: 8502: 8500: 8497: 8495: 8492: 8490: 8487: 8485: 8482: 8480: 8479:Nonhypotenuse 8477: 8476: 8473: 8466: 8462: 8452: 8449: 8447: 8444: 8442: 8439: 8437: 8434: 8432: 8429: 8428: 8425: 8418: 8414: 8404: 8401: 8399: 8396: 8394: 8391: 8389: 8386: 8384: 8381: 8379: 8376: 8374: 8371: 8369: 8366: 8365: 8362: 8357: 8352: 8348: 8338: 8335: 8333: 8330: 8328: 8325: 8323: 8320: 8318: 8315: 8314: 8311: 8304: 8300: 8290: 8287: 8285: 8282: 8280: 8277: 8275: 8272: 8270: 8267: 8265: 8262: 8260: 8257: 8256: 8253: 8248: 8242: 8238: 8228: 8225: 8223: 8220: 8218: 8217:Perfect power 8215: 8213: 8210: 8208: 8207:Seventh power 8205: 8203: 8200: 8198: 8195: 8193: 8190: 8188: 8185: 8183: 8180: 8178: 8175: 8173: 8170: 8168: 8165: 8163: 8160: 8159: 8156: 8151: 8146: 8142: 8138: 8130: 8125: 8123: 8118: 8116: 8111: 8110: 8107: 8095: 8092: 8090: 8087: 8085: 8082: 8080: 8077: 8075: 8072: 8070: 8067: 8065: 8062: 8060: 8057: 8055: 8052: 8051: 8049: 8045: 8039: 8036: 8034: 8033:Polydivisible 8031: 8029: 8026: 8024: 8021: 8019: 8016: 8014: 8011: 8010: 8008: 8005: 8001: 7995: 7992: 7990: 7987: 7984: 7980: 7977: 7975: 7972: 7971: 7969: 7966: 7962: 7956: 7953: 7951: 7948: 7946: 7943: 7941: 7938: 7936: 7935:Superabundant 7933: 7931: 7928: 7926: 7923: 7921: 7918: 7917: 7915: 7911: 7905: 7904:ErdƑs–Nicolas 7902: 7900: 7897: 7895: 7892: 7890: 7887: 7885: 7882: 7880: 7877: 7875: 7872: 7870: 7867: 7865: 7862: 7860: 7857: 7855: 7852: 7851: 7849: 7845: 7839: 7836: 7834: 7831: 7829: 7826: 7824: 7821: 7819: 7816: 7814: 7813:Perfect power 7811: 7809: 7806: 7804: 7801: 7799: 7796: 7794: 7791: 7789: 7786: 7784: 7781: 7779: 7776: 7775: 7773: 7769: 7764: 7754: 7751: 7749: 7746: 7744: 7741: 7739: 7736: 7734: 7731: 7729: 7726: 7725: 7723: 7719: 7710: 7705: 7703: 7698: 7696: 7691: 7690: 7687: 7673:on 2013-05-31 7672: 7668: 7664: 7660: 7655: 7652: 7649: 7646: 7643: 7640: 7637: 7635: 7629: 7624: 7623: 7618: 7615: 7610: 7608: 7605: 7603: 7600:David Moews: 7599: 7595: 7591: 7590: 7585: 7581: 7580: 7576: 7570: 7566: 7562: 7560:1-4020-2546-7 7556: 7552: 7547: 7546: 7539: 7536: 7532: 7529: 7525: 7521: 7517: 7512: 7507: 7503: 7499: 7498: 7493: 7488: 7485: 7484: 7480: 7473: 7469: 7464: 7460: 7456: 7452: 7448: 7444: 7440: 7435: 7432: 7428: 7427: 7422: 7421: 7416: 7406: 7404:9780824796969 7400: 7396: 7395: 7387: 7384: 7379: 7378: 7373: 7367: 7364: 7360: 7357:H. Novarese. 7354: 7351: 7346: 7342: 7338: 7334: 7330: 7326: 7319: 7316: 7311: 7307: 7303: 7299: 7295: 7291: 7284: 7281: 7276: 7272: 7268: 7264: 7260: 7256: 7252: 7248: 7241: 7238: 7233: 7231:9781118188613 7227: 7223: 7222: 7214: 7211: 7204: 7199: 7195: 7191: 7187: 7180: 7177: 7172: 7168: 7161: 7158: 7154: 7148: 7145: 7140: 7136: 7132: 7128: 7124: 7120: 7115: 7110: 7106: 7102: 7095: 7092: 7087: 7083: 7079: 7075: 7071: 7067: 7066: 7058: 7042: 7039: 7035: 7029: 7025: 7011: 7008: 7003: 6999: 6995: 6991: 6986: 6981: 6977: 6973: 6969: 6962: 6959: 6954: 6950: 6946: 6942: 6938: 6934: 6933: 6925: 6918: 6916: 6912: 6907: 6903: 6899: 6895: 6891: 6887: 6883: 6879: 6875: 6871: 6870: 6865: 6859: 6856: 6851: 6847: 6843: 6839: 6834: 6829: 6825: 6821: 6817: 6810: 6807: 6802: 6798: 6794: 6790: 6785: 6780: 6776: 6772: 6771: 6763: 6756: 6754: 6752: 6748: 6743: 6739: 6735: 6731: 6727: 6723: 6719: 6715: 6711: 6707: 6700: 6697: 6692: 6688: 6681: 6678: 6674:(6): 523-527. 6673: 6669: 6662: 6659: 6646: 6642: 6638: 6631: 6628: 6615: 6610: 6606: 6602: 6595: 6588: 6585: 6579: 6574: 6570: 6566: 6565: 6560: 6553: 6550: 6537: 6533: 6529: 6522: 6519: 6513: 6508: 6504: 6500: 6496: 6489: 6486: 6474: 6470: 6463: 6456: 6454: 6450: 6438: 6434: 6430: 6426: 6422: 6418: 6413: 6408: 6404: 6400: 6393: 6386: 6383: 6370: 6365: 6361: 6357: 6350: 6343: 6340: 6328: 6324: 6317: 6310: 6307: 6294: 6289: 6285: 6281: 6277: 6273: 6266: 6259: 6256: 6250: 6246: 6242: 6238: 6233: 6228: 6224: 6220: 6213: 6210: 6197: 6192: 6188: 6184: 6180: 6176: 6169: 6162: 6159: 6154: 6150: 6146: 6142: 6135: 6132: 6119: 6114: 6110: 6106: 6102: 6098: 6091: 6084: 6081: 6076: 6072: 6065: 6058: 6055: 6050: 6046: 6042: 6038: 6034: 6031:(in German). 6030: 6023: 6020: 6015: 6011: 6007: 6003: 5998: 5993: 5989: 5985: 5984: 5976: 5969: 5967: 5965: 5961: 5949: 5945: 5938: 5935: 5932: 5928: 5924: 5919: 5916: 5904: 5897: 5891: 5888: 5883: 5882: 5877: 5871: 5868: 5862: 5861: 5856: 5853: 5846: 5843: 5831: 5825: 5822: 5818: 5814: 5813: 5808: 5804: 5797: 5794: 5789: 5783: 5768: 5767: 5762: 5756: 5754: 5750: 5745: 5743:88-8358-537-2 5739: 5735: 5734: 5726: 5723: 5718: 5716:0-19-515799-0 5712: 5708: 5707: 5699: 5696: 5691: 5690: 5685: 5679: 5676: 5671: 5669:0-486-20430-8 5665: 5661: 5660: 5655: 5650: 5645: 5642: 5638: 5632: 5629: 5624: 5617: 5616: 5613: 5605: 5602: 5598: 5592: 5589: 5585: 5581: 5580: 5573: 5570: 5558: 5554: 5548: 5545: 5540: 5539: 5534: 5528: 5525: 5521: 5515: 5512: 5501: 5497: 5491: 5488: 5481: 5472: 5468: 5445: 5442: 5439: 5434: 5430: 5419: 5411: 5403: 5397: 5384: 5380: 5362: 5359: 5354: 5350: 5339: 5336: 5329: 5325: 5322: 5320: 5317: 5315: 5312: 5310: 5307: 5305: 5302: 5300: 5297: 5295: 5292: 5291: 5287: 5285: 5283: 5282:weird numbers 5278: 5273: 5271: 5243: 5238: 5234: 5230: 5226: 5222: 5218: 5214: 5209: 5207: 5203: 5199: 5195: 5191: 5187: 5183: 5179: 5171: 5162: 5153: 5144: 5135: 5131: 5122: 5118: 5117:Superabundant 5109: 5100: 5091: 5082: 5081:Euler diagram 5078: 5071: 5066: 5062: 5059: 5055: 5052: 5031: 5023: 5015: 4997: 4992: 4985:is less than 4984: 4980: 4965: 4962: 4957: 4953: 4945: 4926: 4923: 4918: 4914: 4905: 4902: 4899: 4895: 4886: 4882: 4878: 4873: 4869: 4868: 4866: 4862: 4845: 4842: 4839: 4835: 4831: 4828: 4825: 4821: 4817: 4814: 4811: 4807: 4803: 4800: 4797: 4793: 4789: 4786: 4783: 4779: 4775: 4772: 4769: 4765: 4761: 4753: 4738: 4735: 4730: 4726: 4723: 4720: 4714: 4709: 4705: 4702: 4699: 4696: 4693: 4690: 4687: 4681: 4676: 4673: 4668: 4663: 4660: 4655: 4650: 4647: 4642: 4637: 4634: 4629: 4624: 4621: 4616: 4611: 4608: 4603: 4598: 4595: 4590: 4585: 4582: 4572: 4571: 4569: 4553: 4550: 4547: 4541: 4533: 4529: 4520: 4516: 4512: 4509: 4508:Gallardo 2010 4505: 4502: 4501:Makowski 1962 4498: 4494: 4493: 4492: 4490: 4486: 4478:Minor results 4477: 4474: 4470: 4468: 4442: 4439: 4436: 4433: 4430: 4425: 4421: 4417: 4413: 4408: 4404: 4401: 4381: 4378: 4375: 4372: 4369: 4364: 4360: 4356: 4353: 4350: 4343: 4340: 4337: 4336: 4333: 4328: 4324: 4317: 4312: 4308: 4304: 4297: 4293: 4276: 4271: 4268: 4265: 4262: 4259: 4256: 4253: 4249: 4242: 4239: 4236: 4225: 4221: 4216: 4212: 4205: 4201: 4198: 4194: 4190: 4185: 4181: 4177: 4174: 4170: 4166: 4161: 4157: 4153: 4150: 4145: 4141: 4137: 4134: 4129: 4125: 4121: 4120: 4119: 4116: 4112: 4105: 4080: 4077: 4074: 4071: 4066: 4063: 4060: 4054: 4047: 4043: 4039: 4034: 4031: 4028: 4021: 4017: 4013: 4008: 4001: 3997: 3993: 3988: 3983: 3980: 3971: 3953: 3950: 3945: 3941: 3938: 3933: 3929: 3925: 3920: 3916: 3910: 3906: 3900: 3896: 3892: 3885: 3868: 3864: 3861: 3858: 3855: 3849: 3844: 3840: 3836: 3833: 3830: 3827: 3822: 3818: 3814: 3811: 3806: 3802: 3798: 3795: 3790: 3786: 3782: 3779: 3776: 3769: 3748: 3745: 3742: 3738: 3734: 3729: 3726: 3723: 3719: 3711: 3707: 3704: 3697: 3694: 3690: 3676: 3671: 3667: 3664: 3661: 3650: 3646: 3643: 3639: 3636: 3632: 3628: 3621: 3617: 3614: 3613: 3611: 3595: 3588: 3584: 3580: 3575: 3571: 3567: 3560: 3556: 3552: 3547: 3543: 3537: 3533: 3529: 3526: 3519: 3518: 3517: 3516: 3512: 3509: 3506: 3502: 3498: 3495: 3481: 3475: 3470: 3467: 3456: 3438: 3433: 3430: 3419: 3405: 3399: 3394: 3391: 3380: 3376: 3373: 3369: 3365: 3361: 3358: 3355: 3352: 3349: 3346: 3345: 3344: 3342: 3337: 3335: 3331: 3327: 3323: 3318: 3311: 3294: 3292: 3290: 3286: 3281: 3279: 3274: 3255: 3252:1111111000000 3251: 3247: 3238: 3234: 3230: 3225: 3221: 3217: 3212: 3208: 3204: 3199: 3195: 3191: 3186: 3182: 3178: 3173: 3169: 3165: 3160: 3156: 3148: 3143: 3139: 3129: 3125: 3121: 3114: 3110: 3106: 3101: 3097: 3093: 3088: 3084: 3080: 3075: 3071: 3067: 3062: 3058: 3052: 3047: 3043: 3033: 3029: 3025: 3018: 3014: 3010: 3005: 3001: 2997: 2992: 2988: 2982: 2977: 2973: 2963: 2959: 2955: 2948: 2944: 2940: 2935: 2931: 2925: 2920: 2916: 2903: 2899: 2878: 2872: 2869: 2864: 2860: 2851: 2848: 2845: 2841: 2831: 2810: 2807: 2802: 2798: 2789: 2786: 2783: 2779: 2768: 2747: 2744: 2739: 2735: 2726: 2723: 2720: 2716: 2695: 2634: 2619: 2615: 2608: 2605: 2600: 2596: 2588: 2584: 2581: 2578: 2575: 2572: 2567: 2560: 2557: 2552: 2548: 2541: 2535: 2532: 2527: 2523: 2513: 2510: 2507: 2502: 2499: 2494: 2490: 2485: 2475: 2456: 2452: 2448: 2443: 2439: 2435: 2430: 2426: 2422: 2419: 2416: 2411: 2407: 2403: 2398: 2394: 2390: 2385: 2381: 2377: 2375: 2365: 2362: 2359: 2356: 2353: 2350: 2347: 2344: 2341: 2338: 2335: 2332: 2329: 2326: 2324: 2315: 2312: 2307: 2303: 2294: 2290: 2286: 2284: 2279: 2270: 2266: 2262: 2257: 2253: 2249: 2244: 2240: 2236: 2231: 2227: 2223: 2218: 2214: 2210: 2205: 2201: 2197: 2192: 2188: 2184: 2179: 2175: 2171: 2169: 2159: 2156: 2153: 2150: 2147: 2144: 2141: 2138: 2135: 2132: 2129: 2126: 2123: 2120: 2118: 2109: 2106: 2101: 2097: 2088: 2084: 2080: 2078: 2073: 2064: 2060: 2056: 2051: 2047: 2043: 2038: 2034: 2030: 2025: 2021: 2017: 2015: 2005: 2002: 1999: 1996: 1993: 1990: 1987: 1984: 1981: 1978: 1975: 1972: 1969: 1966: 1964: 1955: 1952: 1947: 1943: 1934: 1930: 1926: 1924: 1919: 1910: 1906: 1902: 1897: 1893: 1889: 1887: 1877: 1874: 1871: 1868: 1865: 1862: 1859: 1856: 1853: 1850: 1847: 1844: 1841: 1838: 1836: 1827: 1824: 1819: 1815: 1806: 1802: 1798: 1796: 1791: 1784: 1781: 1778: 1775: 1772: 1769: 1766: 1764: 1755: 1752: 1747: 1743: 1734: 1730: 1726: 1724: 1719: 1707: 1693: 1690: 1684: 1680: 1677: 1674: 1668: 1644: 1640: 1637: 1634: 1628: 1619: 1600: 1596: 1593: 1588: 1584: 1571: 1553: 1550: 1547: 1543: 1522: 1519: 1514: 1510: 1501: 1482: 1479: 1474: 1470: 1443: 1440: 1435: 1431: 1422: 1419: 1416: 1412: 1402: 1400: 1396: 1376: 1371: 1363: 1362: 1361: 1344: 1341: 1336: 1332: 1323: 1320: 1317: 1313: 1304: 1299: 1297: 1293: 1274: 1271: 1266: 1262: 1253: 1250: 1247: 1243: 1234: 1230: 1214: 1211: 1206: 1202: 1178: 1175: 1170: 1166: 1157: 1154: 1151: 1147: 1136: 1134: 1129: 1115: 1112: 1107: 1103: 1083:with a prime 1070: 1067: 1062: 1058: 1033: 1030: 1025: 1021: 1012: 1011:number theory 1008: 1004: 1001:are known as 988: 985: 980: 976: 966: 949: 946: 943: 940: 937: 934: 928: 925: 920: 916: 907: 903: 898: 896: 891: 888: 885: 878: 875: 872: 869: 866: 863: 857: 854: 849: 845: 836: 832: 827: 825: 820: 817: 814: 807: 804: 801: 798: 795: 792: 786: 783: 778: 774: 765: 761: 756: 754: 749: 746: 743: 736: 733: 730: 727: 724: 721: 715: 712: 707: 703: 694: 690: 685: 683: 678: 675: 672: 660: 640: 634: 631: 626: 622: 613: 610: 607: 603: 593: 591: 590: 573: 570: 565: 561: 537: 534: 529: 525: 516: 513: 510: 506: 497: 491: 476: 468: 466: 464: 460: 456: 452: 448: 444: 424: 421: 416: 412: 388: 385: 380: 376: 367: 364: 361: 357: 346: 344: 340: 332: 330: 327: 325: 321: 317: 301: 281: 278: 273: 269: 261: 245: 225: 221: 214: 211: 208: 202: 194: 190: 186: 182: 172: 171: 164: 162: 144: 140: 119: 116: 113: 107: 99: 95: 86: 81: 79: 75: 71: 67: 62: 60: 56: 52: 48: 47:number theory 39: 33: 19: 9761:Transposable 9625:Narcissistic 9532:Digital root 9452:Super-Poulet 9412:Jordan–PĂłlya 9361:prime factor 9303: 9266:Noncototient 9233:Almost prime 9215:Superperfect 9190:Refactorable 9185:Quasiperfect 9169: 9160:Hyperperfect 9001:Pseudoprimes 8972:Wall–Sun–Sun 8907:Ordered Bell 8877:Fuss–Catalan 8789:non-centered 8739:Dodecahedral 8716:non-centered 8602:non-centered 8504:Wolstenholme 8249:× 2 ± 1 8246: 8245:Of the form 8212:Eighth power 8192:Fourth power 8094:Superperfect 8089:Refactorable 7884:Superperfect 7879:Hyperperfect 7864:Quasiperfect 7853: 7748:Prime factor 7675:. Retrieved 7671:the original 7662: 7620: 7587: 7544: 7534: 7527: 7501: 7495: 7471: 7467: 7442: 7438: 7424: 7393: 7386: 7376: 7366: 7358: 7353: 7328: 7324: 7318: 7293: 7289: 7283: 7250: 7246: 7240: 7220: 7213: 7193: 7189: 7179: 7170: 7166: 7160: 7152: 7147: 7107:(1): 15–21. 7104: 7100: 7094: 7072:(1): 25–28. 7069: 7063: 7010: 6978:(1): 13–15. 6975: 6971: 6961: 6939:(1): 70–76. 6936: 6930: 6873: 6867: 6858: 6823: 6819: 6809: 6774: 6768: 6712:(1): 52–53. 6709: 6705: 6699: 6690: 6686: 6680: 6671: 6667: 6661: 6649:. Retrieved 6644: 6640: 6630: 6618:. Retrieved 6604: 6600: 6587: 6568: 6562: 6552: 6540:. Retrieved 6535: 6531: 6521: 6502: 6498: 6488: 6476:. Retrieved 6472: 6468: 6440:. Retrieved 6412:math/0602485 6402: 6398: 6385: 6373:. Retrieved 6359: 6355: 6342: 6330:. Retrieved 6326: 6322: 6309: 6297:. Retrieved 6275: 6271: 6258: 6222: 6218: 6212: 6200:. Retrieved 6178: 6174: 6161: 6144: 6140: 6134: 6122:. Retrieved 6100: 6096: 6083: 6074: 6070: 6057: 6032: 6028: 6022: 5987: 5981: 5953:10 September 5951:. Retrieved 5947: 5937: 5918: 5906:. Retrieved 5902: 5890: 5880: 5870: 5858: 5845: 5834:. Retrieved 5830:"GIMPS Home" 5824: 5810: 5796: 5770:. Retrieved 5764: 5732: 5725: 5705: 5698: 5688: 5678: 5658: 5644: 5636: 5631: 5622: 5615: 5611: 5604: 5591: 5577: 5572: 5560:. Retrieved 5556: 5547: 5537: 5527: 5514: 5503:. Retrieved 5499: 5490: 5417: 5409: 5401: 5382: 5338: 5274: 5236: 5232: 5228: 5224: 5220: 5210: 5189: 5175: 5151: 5058:digital root 5013: 4982: 4944:Fermat prime 4864: 4567: 4518: 4496: 4481: 4472: 4464: 4338: 4331: 4326: 4322: 4315: 4306: 4302: 4295: 4223: 4219: 4214: 4210: 4203: 4196: 4192: 4188: 4183: 4179: 4172: 4159: 4155: 4143: 4139: 4127: 4123: 4114: 4110: 4103: 4101: 3692: 3648: 3637: 3630: 3626: 3619: 3615: 3510: 3504: 3500: 3496: 3378: 3371: 3367: 3363: 3359: 3353: 3347: 3340: 3338: 3314: 3282: 3275: 2904: 2897: 2832: 2694:digital root 2635: 2476: 1708: 1403: 1380: 1300: 1130: 967: 659:prime number 594: 587: 498:proved that 494: 336: 328: 188: 184: 180: 169: 165: 82: 63: 50: 44: 9782:Extravagant 9777:Equidigital 9732:permutation 9691:Palindromic 9665:Automorphic 9563:Sum-product 9542:Sum-product 9497:Persistence 9392:ErdƑs–Woods 9314:Untouchable 9195:Semiperfect 9145:Hemiperfect 8806:Tesseractic 8744:Icosahedral 8724:Tetrahedral 8655:Dodecagonal 8356:Recursively 8227:Prime power 8202:Sixth power 8197:Fifth power 8177:Power of 10 8135:Classes of 8018:Extravagant 8013:Equidigital 7974:Untouchable 7894:Semiperfect 7874:Hemiperfect 7803:Square-free 7667:Brady Haran 7663:Numberphile 7533:Riesel, H. 6620:29 November 6035:: 202–211. 5903:Harvard.edu 5213:fixed point 5176:The sum of 5065:square-free 4515:reciprocals 4485:Richard Guy 4226:twos, then 3695:exceeds 10. 3651:is at most 3644:4) (Euler). 1391:2 × (2 − 1) 455:City of God 260:of the form 258:is a prime 85:aliquot sum 10043:Categories 9994:Graphemics 9867:Pernicious 9721:Undulating 9696:Pandigital 9670:Trimorphic 9271:Nontotient 9120:Arithmetic 8734:Octahedral 8635:Heptagonal 8625:Pentagonal 8610:Triangular 8451:SierpiƄski 8373:Jacobsthal 8172:Power of 3 8167:Power of 2 8054:Arithmetic 8047:Other sets 8006:-dependent 7677:2013-04-02 7569:1079.11001 7290:Arch. Math 7190:Elem. Math 7167:Elem. Math 7114:1706.09341 6693:: 896–904. 6651:7 December 6614:2303.11974 6332:6 December 6232:1810.11734 6014:1263.11005 5836:2022-07-21 5505:2024-03-21 5482:References 5398:—that is, 5240:, and the 5194:numerology 2702:1 + 9 = 10 1535:) and the 1133:Nicomachus 586:is prime ( 473:See also: 343:Nicomachus 18:8589869056 9751:Parasitic 9600:Factorion 9527:Digit sum 9519:Digit sum 9337:Fortunate 9324:Primorial 9238:Semiprime 9175:Practical 9140:Descartes 9135:Deficient 9125:Betrothed 8967:Wieferich 8796:Pentatope 8759:pyramidal 8650:Decagonal 8645:Nonagonal 8640:Octagonal 8630:Hexagonal 8489:Practical 8436:Congruent 8368:Fibonacci 8332:Loeschian 8084:Descartes 8059:Deficient 7994:Betrothed 7899:Practical 7788:Semiprime 7783:Composite 7622:MathWorld 7594:EMS Press 7459:115983363 7345:122353640 7325:Math. Ann 7310:122525522 7275:125545112 7173:(5): 109. 7139:119175632 7131:1730-6302 7078:0015-0517 7043:β 7030:α 6994:1088-6826 6945:0015-0517 6906:122452828 6890:1435-5345 6842:1446-8107 6793:0025-5718 6742:121251041 6726:1420-8938 6538:: A14–A22 6375:13 August 6077:(4): 244. 6049:120754476 6006:0025-5718 5860:MathWorld 5440:− 5360:− 5182:deficient 5170:Deficient 5161:Composite 5063:The only 4903:− 4724:⋅ 4530:σ 4467:Sylvester 4465:In 1888, 4354:≤ 4277:α 4263:≤ 4257:≤ 4240:− 4222:ones and 4167:3) or 2 ( 4078:⁡ 4064:⁡ 4032:⋯ 3926:⋯ 3862:− 3850:≥ 3831:⋯ 3777:α 3735:− 3665:− 3568:⋯ 3538:α 3126:111110000 2870:− 2849:− 2808:− 2787:− 2745:− 2724:− 2706:1 + 0 = 1 2606:− 2585:× 2542:× 2533:− 2500:− 2420:⋯ 2348:⋯ 2313:− 2142:⋯ 2107:− 1988:⋯ 1953:− 1825:− 1753:− 1691:− 1638:− 1551:− 1520:− 1480:− 1441:− 1420:− 1395:not known 1342:− 1321:− 1272:− 1251:− 1212:− 1176:− 1155:− 1113:− 1068:− 1031:− 986:− 941:× 926:− 870:× 855:− 799:× 784:− 728:× 713:− 632:− 611:− 571:− 535:− 514:− 449:, and by 422:− 386:− 365:− 279:− 168:Euclid's 141:σ 96:σ 9823:Friedman 9756:Primeval 9701:Repdigit 9658:-related 9605:Kaprekar 9579:Meertens 9502:Additive 9489:dynamics 9397:Friendly 9309:Sociable 9299:Amicable 9110:Abundant 9090:dynamics 8912:Schröder 8902:Narayana 8872:Eulerian 8862:Delannoy 8857:Dedekind 8678:centered 8544:centered 8431:Amenable 8388:Narayana 8378:Leonardo 8274:Mersenne 8222:Powerful 8162:Achilles 8069:Solitary 8064:Friendly 7989:Sociable 7979:Amicable 7967:-related 7920:Abundant 7818:Achilles 7808:Powerful 7721:Overview 7474:: 69–72. 7426:Elements 7423:Euclid, 7374:(1919). 6601:Integers 6542:23 March 6532:Integers 6478:7 August 6469:Integers 6442:30 March 6323:Integers 6299:30 March 6249:62885986 6202:30 March 6124:30 March 5927:Archived 5878:(1919). 5782:cite web 5686:(1919). 5656:(1925). 5535:(1919). 5500:oeis.org 5288:See also 5202:sociable 5198:amicable 5186:abundant 5090:Abundant 5049:, using 5012:, where 4469:stated: 4321:= ... = 4138:Not all 4122:Not all 3350:> 10. 2280:33550336 589:Elements 170:Elements 59:divisors 9996:related 9960:related 9924:related 9922:Sorting 9807:Vampire 9792:Harshad 9734:related 9706:Repunit 9620:Lychrel 9595:Dudeney 9447:StĂžrmer 9442:Sphenic 9427:Regular 9365:divisor 9304:Perfect 9200:Sublime 9170:Perfect 8897:Motzkin 8852:Catalan 8393:Padovan 8327:Leyland 8322:Idoneal 8317:Hilbert 8289:Woodall 8074:Sublime 8028:Harshad 7854:Perfect 7838:Unusual 7828:Regular 7798:Sphenic 7733:Divisor 7647:(GIMPS) 7596:, 2001 7520:2005530 7417:Sources 7267:3619053 7086:0354538 7002:0292740 6953:0786364 6898:0044579 6850:0869751 6801:2904601 6734:0258723 6647:: 23–30 6437:2767519 6417:Bibcode 6280:Bibcode 6183:Bibcode 6105:Bibcode 5908:16 June 5772:28 July 5471:A002515 5469::  5215:of the 5190:perfect 5168:  5159:  5152:Perfect 5150:  5141:  5128:  5115:  5106:  5097:  5088:  4335:, then 4154:If all 3618:,  3612:where: 3503:, then 1373:in the 1370:A000043 333:History 181:perfect 159:is the 9862:Odious 9787:Frugal 9741:Cyclic 9730:Digit- 9437:Smooth 9422:Pronic 9382:Cyclic 9359:Other 9332:Euclid 8982:Wilson 8956:Primes 8615:Square 8484:Polite 8446:Riesel 8441:Knödel 8403:Perrin 8284:Thabit 8269:Fermat 8259:Cullen 8182:Square 8150:Powers 8023:Frugal 7983:Triple 7823:Smooth 7793:Pronic 7567:  7557:  7518:  7457:  7401:  7343:  7308:  7273:  7265:  7228:  7137:  7129:  7084:  7076:  7000:  6992:  6951:  6943:  6904:  6896:  6888:  6848:  6840:  6799:  6791:  6740:  6732:  6724:  6435:  6247:  6047:  6012:  6004:  5740:  5713:  5666:  5166:  5157:  5148:  5139:  5126:  5113:  5104:  5095:  5086:  4858:, etc. 2704:, and 2658:= 8128 1194:where 1131:While 496:Euclid 447:Origen 404:where 193:Euclid 132:where 9903:Prime 9898:Lucky 9887:sieve 9816:Other 9802:Smith 9682:Digit 9640:Happy 9615:Keith 9588:Other 9432:Rough 9402:Giuga 8867:Euler 8729:Cubic 8383:Lucas 8279:Proth 8038:Smith 7955:Weird 7833:Rough 7778:Prime 7553:–98. 7516:JSTOR 7455:S2CID 7341:S2CID 7306:S2CID 7271:S2CID 7263:JSTOR 7135:S2CID 7109:arXiv 7060:(PDF) 6927:(PDF) 6902:S2CID 6765:(PDF) 6738:S2CID 6609:arXiv 6597:(PDF) 6465:(PDF) 6433:S2CID 6407:arXiv 6395:(PDF) 6352:(PDF) 6319:(PDF) 6268:(PDF) 6245:S2CID 6227:arXiv 6171:(PDF) 6093:(PDF) 6067:(PDF) 6045:S2CID 5978:(PDF) 5899:(PDF) 5619:(PDF) 5562:9 May 5394:is a 5330:Notes 5143:Weird 5132:and 5119:and 3287:(cf. 3030:11100 2682:= 903 2650:= 496 1303:GIMPS 950:8128. 653:with 347:every 187:, or 185:ideal 53:is a 9857:Evil 9537:Self 9487:and 9377:Blum 9088:and 8892:Lobb 8847:Cake 8842:Bell 8592:Star 8499:Ulam 8398:Pell 8187:Cube 8004:Base 7631:OEIS 7555:ISBN 7472:1937 7443:1941 7399:ISBN 7226:ISBN 7127:ISSN 7074:ISSN 6990:ISSN 6941:ISSN 6886:ISSN 6838:ISSN 6789:ISSN 6722:ISSN 6653:2018 6622:2023 6544:2021 6480:2021 6444:2011 6377:2015 6334:2021 6301:2011 6204:2011 6126:2011 6002:ISSN 5955:2020 5910:2023 5788:link 5774:2024 5738:ISBN 5711:ISBN 5664:ISBN 5564:2018 5467:OEIS 5235:) − 5227:) = 4513:The 4405:< 4394:and 4202:If ( 4055:> 3939:< 3708:< 3140:8128 2688:2730 2674:= 55 2642:= 28 2366:8191 2360:8190 2354:8189 2074:8128 1616:-th 1568:-th 1498:-th 1375:OEIS 1360:for 78:8128 76:and 49:, a 9975:Ban 9363:or 8882:Lah 7565:Zbl 7506:doi 7447:doi 7333:doi 7329:131 7298:doi 7255:doi 7198:doi 7119:doi 7105:156 6980:doi 6878:doi 6874:188 6828:doi 6779:doi 6714:doi 6573:doi 6507:doi 6425:doi 6364:doi 6288:doi 6237:doi 6191:doi 6149:doi 6113:doi 6037:doi 6010:Zbl 5992:doi 5576:In 5420:+ 1 5412:+ 1 5404:+ 1 5379:mod 4570:): 4487:'s 4313:If 4169:mod 4165:mod 4151:5). 4149:mod 4135:3). 4133:mod 3865:224 3642:mod 3291:). 3044:496 2960:110 2900:− 1 2769:all 2666:= 3 2656:127 2453:127 2440:125 2427:123 2160:127 2154:126 2148:125 1920:496 1706:): 1137:all 944:127 879:496 191:). 74:496 45:In 10045:: 7665:. 7661:. 7619:. 7592:, 7586:, 7563:. 7551:15 7514:. 7502:27 7500:. 7494:. 7470:. 7453:. 7441:. 7339:. 7327:. 7304:. 7292:. 7269:. 7261:. 7251:83 7249:. 7194:65 7192:. 7188:. 7171:17 7169:. 7133:. 7125:. 7117:. 7103:. 7082:MR 7080:. 7070:13 7068:. 7062:. 6998:MR 6996:. 6988:. 6976:32 6974:. 6970:. 6949:MR 6947:. 6937:23 6935:. 6929:. 6914:^ 6900:. 6894:MR 6892:. 6884:. 6872:. 6846:MR 6844:. 6836:. 6824:42 6822:. 6818:. 6797:MR 6795:. 6787:. 6775:81 6773:. 6767:. 6750:^ 6736:. 6730:MR 6728:. 6720:. 6710:21 6708:. 6691:14 6689:. 6672:16 6670:. 6645:16 6643:. 6639:. 6607:. 6605:23 6603:. 6599:. 6569:83 6567:. 6561:. 6534:. 6530:. 6503:89 6501:. 6497:. 6473:21 6471:. 6467:. 6452:^ 6431:. 6423:. 6415:. 6403:76 6401:. 6397:. 6360:84 6358:. 6354:. 6327:21 6325:. 6321:. 6286:. 6276:69 6274:. 6270:. 6243:. 6235:. 6223:15 6221:. 6189:. 6179:68 6177:. 6173:. 6143:. 6111:. 6101:77 6099:. 6095:. 6075:35 6073:. 6069:. 6043:. 6033:52 6008:. 6000:. 5988:81 5986:. 5980:. 5963:^ 5946:. 5925:. 5901:. 5857:. 5815:, 5809:, 5805:, 5784:}} 5780:{{ 5763:. 5752:^ 5621:. 5555:. 5498:. 5377:1 5284:. 5275:A 5272:. 5208:. 4784:14 4770:28 4510:). 4503:). 4491:: 4330:= 4118:. 4075:ln 4061:ln 3954:26 3951:17 3869:37 3856:99 3280:. 3187:10 3174:11 3161:12 3144:10 3048:10 2978:10 2974:28 2921:10 2830:. 2700:, 2684:, 2680:42 2676:, 2672:10 2668:, 2652:, 2648:31 2644:, 2308:13 2295:12 2267:15 2254:13 2241:11 2006:31 2000:30 1994:29 1792:28 1377:). 1298:. 938:64 873:31 867:16 808:28 657:a 326:. 183:, 163:. 80:. 72:, 70:28 68:, 8247:a 8128:e 8121:t 8114:v 7985:) 7981:( 7708:e 7701:t 7694:v 7680:. 7625:. 7571:. 7522:. 7508:: 7461:. 7449:: 7409:. 7407:. 7347:. 7335:: 7312:. 7300:: 7294:6 7277:. 7257:: 7235:. 7208:. 7206:. 7200:: 7141:. 7121:: 7111:: 7088:. 7057:" 7040:2 7036:M 7026:p 7004:. 6982:: 6955:. 6908:. 6880:: 6852:. 6830:: 6803:. 6781:: 6744:. 6716:: 6655:. 6624:. 6611:: 6581:. 6575:: 6546:. 6536:3 6515:. 6509:: 6482:. 6446:. 6427:: 6419:: 6409:: 6379:. 6366:: 6336:. 6303:. 6290:: 6282:: 6253:. 6251:. 6239:: 6229:: 6206:. 6193:: 6185:: 6155:. 6151:: 6145:8 6128:. 6115:: 6107:: 6051:. 6039:: 6016:. 5994:: 5957:. 5912:. 5863:. 5839:. 5790:) 5776:. 5746:. 5719:. 5672:. 5625:. 5566:. 5522:. 5508:. 5474:. 5461:p 5446:, 5443:1 5435:p 5431:2 5418:p 5416:2 5410:p 5408:2 5402:p 5400:2 5392:p 5383:p 5381:2 5363:1 5355:p 5351:2 5254:S 5237:n 5233:n 5231:( 5229:σ 5225:n 5223:( 5221:s 5053:. 5037:) 5032:n 5027:( 5024:o 5014:c 4998:n 4993:c 4983:n 4966:1 4963:+ 4958:n 4954:2 4930:) 4927:1 4924:+ 4919:n 4915:2 4911:( 4906:1 4900:n 4896:2 4874:. 4865:N 4846:2 4843:= 4840:1 4836:/ 4832:1 4829:+ 4826:2 4822:/ 4818:1 4815:+ 4812:4 4808:/ 4804:1 4801:+ 4798:7 4794:/ 4790:1 4787:+ 4780:/ 4776:1 4773:+ 4766:/ 4762:1 4751:; 4739:2 4736:= 4731:6 4727:6 4721:2 4715:= 4710:6 4706:6 4703:+ 4700:3 4697:+ 4694:2 4691:+ 4688:1 4682:= 4677:6 4674:6 4669:+ 4664:6 4661:3 4656:+ 4651:6 4648:2 4643:+ 4638:6 4635:1 4630:= 4625:1 4622:1 4617:+ 4612:2 4609:1 4604:+ 4599:3 4596:1 4591:+ 4586:6 4583:1 4568:n 4554:n 4551:2 4548:= 4545:) 4542:n 4539:( 4534:1 4519:N 4497:n 4459:. 4443:3 4440:+ 4437:e 4434:8 4431:+ 4426:2 4422:e 4418:2 4414:4 4409:2 4402:N 4382:2 4379:+ 4376:e 4373:8 4370:+ 4365:2 4361:e 4357:2 4351:k 4339:e 4332:e 4327:k 4323:e 4319:1 4316:e 4307:k 4303:e 4299:1 4296:e 4294:( 4291:. 4272:+ 4269:t 4266:2 4260:u 4254:4 4250:/ 4246:) 4243:1 4237:t 4234:( 4224:u 4220:t 4215:k 4211:e 4207:1 4204:e 4199:. 4197:S 4193:N 4189:S 4184:i 4180:e 4173:N 4160:i 4156:e 4144:i 4140:e 4128:i 4124:e 4115:k 4111:e 4107:1 4104:e 4096:. 4081:2 4072:2 4067:k 4048:k 4044:p 4040:1 4035:+ 4029:+ 4022:2 4018:p 4014:1 4009:+ 4002:1 3998:p 3994:1 3989:+ 3984:q 3981:1 3969:. 3946:N 3942:2 3934:k 3930:p 3921:3 3917:p 3911:2 3907:p 3901:1 3897:p 3893:q 3883:. 3859:k 3845:k 3841:e 3837:2 3834:+ 3828:+ 3823:3 3819:e 3815:2 3812:+ 3807:2 3803:e 3799:2 3796:+ 3791:1 3787:e 3783:2 3780:+ 3754:) 3749:1 3746:+ 3743:k 3739:2 3730:1 3727:+ 3724:k 3720:4 3716:( 3712:2 3705:N 3693:N 3677:. 3672:2 3668:1 3662:k 3649:N 3638:q 3631:k 3627:p 3623:1 3620:p 3616:q 3596:, 3589:k 3585:e 3581:2 3576:k 3572:p 3561:1 3557:e 3553:2 3548:1 3544:p 3534:q 3530:= 3527:N 3511:N 3505:N 3501:N 3497:N 3482:. 3476:6 3471:N 3468:2 3454:. 3439:5 3434:N 3431:2 3406:. 3400:3 3395:N 3392:3 3379:N 3372:N 3368:N 3364:N 3360:N 3354:N 3348:N 3341:N 3303:: 3256:2 3248:= 3239:6 3235:2 3231:+ 3226:7 3222:2 3218:+ 3213:8 3209:2 3205:+ 3200:9 3196:2 3192:+ 3183:2 3179:+ 3170:2 3166:+ 3157:2 3149:= 3130:2 3122:= 3115:4 3111:2 3107:+ 3102:5 3098:2 3094:+ 3089:6 3085:2 3081:+ 3076:7 3072:2 3068:+ 3063:8 3059:2 3053:= 3034:2 3026:= 3019:2 3015:2 3011:+ 3006:3 3002:2 2998:+ 2993:4 2989:2 2983:= 2964:2 2956:= 2949:1 2945:2 2941:+ 2936:2 2932:2 2926:= 2917:6 2898:p 2893:p 2879:, 2876:) 2873:1 2865:p 2861:2 2857:( 2852:1 2846:p 2842:2 2828:m 2814:) 2811:1 2803:m 2799:2 2795:( 2790:1 2784:m 2780:2 2765:p 2751:) 2748:1 2740:p 2736:2 2732:( 2727:1 2721:p 2717:2 2686:T 2678:T 2670:T 2664:2 2662:T 2654:T 2646:T 2640:7 2638:T 2620:3 2616:/ 2612:) 2609:2 2601:p 2597:2 2593:( 2589:T 2582:9 2579:+ 2576:1 2573:= 2568:2 2564:) 2561:1 2558:+ 2553:p 2549:2 2545:( 2539:) 2536:2 2528:p 2524:2 2520:( 2514:+ 2511:1 2508:= 2503:1 2495:p 2491:2 2486:T 2457:3 2449:+ 2444:3 2436:+ 2431:3 2423:+ 2417:+ 2412:3 2408:5 2404:+ 2399:3 2395:3 2391:+ 2386:3 2382:1 2378:= 2363:+ 2357:+ 2351:+ 2345:+ 2342:3 2339:+ 2336:2 2333:+ 2330:1 2327:= 2319:) 2316:1 2304:2 2300:( 2291:2 2287:= 2271:3 2263:+ 2258:3 2250:+ 2245:3 2237:+ 2232:3 2228:9 2224:+ 2219:3 2215:7 2211:+ 2206:3 2202:5 2198:+ 2193:3 2189:3 2185:+ 2180:3 2176:1 2172:= 2157:+ 2151:+ 2145:+ 2139:+ 2136:3 2133:+ 2130:2 2127:+ 2124:1 2121:= 2113:) 2110:1 2102:7 2098:2 2094:( 2089:6 2085:2 2081:= 2065:3 2061:7 2057:+ 2052:3 2048:5 2044:+ 2039:3 2035:3 2031:+ 2026:3 2022:1 2018:= 2003:+ 1997:+ 1991:+ 1985:+ 1982:3 1979:+ 1976:2 1973:+ 1970:1 1967:= 1959:) 1956:1 1948:5 1944:2 1940:( 1935:4 1931:2 1927:= 1911:3 1907:3 1903:+ 1898:3 1894:1 1890:= 1878:7 1875:+ 1872:6 1869:+ 1866:5 1863:+ 1860:4 1857:+ 1854:3 1851:+ 1848:2 1845:+ 1842:1 1839:= 1831:) 1828:1 1820:3 1816:2 1812:( 1807:2 1803:2 1799:= 1785:, 1782:3 1779:+ 1776:2 1773:+ 1770:1 1767:= 1759:) 1756:1 1748:2 1744:2 1740:( 1735:1 1731:2 1727:= 1720:6 1694:1 1685:2 1681:1 1678:+ 1675:p 1669:2 1645:2 1641:1 1635:p 1629:2 1601:3 1597:1 1594:+ 1589:p 1585:2 1554:1 1548:p 1544:2 1523:1 1515:p 1511:2 1486:) 1483:1 1475:p 1471:2 1467:( 1447:) 1444:1 1436:p 1432:2 1428:( 1423:1 1417:p 1413:2 1387:p 1383:p 1365:p 1348:) 1345:1 1337:p 1333:2 1329:( 1324:1 1318:p 1314:2 1278:) 1275:1 1267:p 1263:2 1259:( 1254:1 1248:p 1244:2 1215:1 1207:n 1203:2 1182:) 1179:1 1171:n 1167:2 1163:( 1158:1 1152:n 1148:2 1116:1 1108:p 1104:2 1093:p 1085:p 1071:1 1063:p 1059:2 1048:p 1034:1 1026:p 1022:2 989:1 981:p 977:2 947:= 935:= 932:) 929:1 921:7 917:2 913:( 908:6 904:2 899:: 892:7 889:= 886:p 876:= 864:= 861:) 858:1 850:5 846:2 842:( 837:4 833:2 828:: 821:5 818:= 815:p 805:= 802:7 796:4 793:= 790:) 787:1 779:3 775:2 771:( 766:2 762:2 757:: 750:3 747:= 744:p 737:6 734:= 731:3 725:2 722:= 719:) 716:1 708:2 704:2 700:( 695:1 691:2 686:: 679:2 676:= 673:p 655:p 641:, 638:) 635:1 627:p 623:2 619:( 614:1 608:p 604:2 574:1 566:p 562:2 541:) 538:1 530:p 526:2 522:( 517:1 511:p 507:2 483:: 439:n 425:1 417:n 413:2 392:) 389:1 381:n 377:2 373:( 368:1 362:n 358:2 302:p 282:1 274:p 270:2 246:q 226:2 222:/ 218:) 215:1 212:+ 209:q 206:( 203:q 179:( 145:1 120:n 117:2 114:= 111:) 108:n 105:( 100:1 66:6 34:. 20:)

Index

8589869056
Perfect Number (film)

number theory
positive integer
divisors
6
28
496
8128
aliquot sum
sum-of-divisors function
Euclid's Elements
Euclid
of the form
Mersenne prime
Leonhard Euler
Euclid–Euler theorem
Greek mathematics
Nicomachus
Philo of Alexandria
Origen
Didymus the Blind
City of God
Ismail ibn Fallƫs
Pietro Cataldi
Euclid–Euler theorem
(more unsolved problems in mathematics)
Euclid
Elements

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