20721640

素因数分解:

$2^3\times 5^1\times {\mathrm{17}}^1\times {\mathrm{31}}^1\times {\mathrm{983}}^1$

素因数の和:1042

約数の個数: 64

約数和(自身を含む): 51010560

約数和(自身を除く): 30288920

約数列:

[1, 2, 4, 5, 8, 10, 17, 20, 31, 34, 40, 62, 68, 85, 124, 136, 155, 170, 248, 310, 340, 527, 620, 680, 983, 1054, 1240, 1966, 2108, 2635, 3932, 4216, 4915, 5270, 7864, 9830, 10540, 16711, 19660, 21080, 30473, 33422, 39320, 60946, 66844, 83555, 121892, 133688, 152365, 167110, 243784, 304730, 334220, 518041, 609460, 668440, 1036082, 1218920, 2072164, 2590205, 4144328, 5180410, 10360820, 20721640]

約数ペア:

[(1, 20721640), (2, 10360820), (4, 5180410), (5, 4144328), (8, 2590205), (10, 2072164), (17, 1218920), (20, 1036082), (31, 668440), (34, 609460), (40, 518041), (62, 334220), (68, 304730), (85, 243784), (124, 167110), (136, 152365), (155, 133688), (170, 121892), (248, 83555), (310, 66844), (340, 60946), (527, 39320), (620, 33422), (680, 30473), (983, 21080), (1054, 19660), (1240, 16711), (1966, 10540), (2108, 9830), (2635, 7864), (3932, 5270), (4216, 4915)]