19968040

素因数分解:

$2^3\times 5^1\times {\mathrm{71}}^1\times {\mathrm{79}}^1\times {\mathrm{89}}^1$

素因数の和:250

約数の個数: 64

約数和(自身を含む): 46656000

約数和(自身を除く): 26687960

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 71, 79, 89, 142, 158, 178, 284, 316, 355, 356, 395, 445, 568, 632, 710, 712, 790, 890, 1420, 1580, 1780, 2840, 3160, 3560, 5609, 6319, 7031, 11218, 12638, 14062, 22436, 25276, 28045, 28124, 31595, 35155, 44872, 50552, 56090, 56248, 63190, 70310, 112180, 126380, 140620, 224360, 252760, 281240, 499201, 998402, 1996804, 2496005, 3993608, 4992010, 9984020, 19968040]

約数ペア:

[(1, 19968040), (2, 9984020), (4, 4992010), (5, 3993608), (8, 2496005), (10, 1996804), (20, 998402), (40, 499201), (71, 281240), (79, 252760), (89, 224360), (142, 140620), (158, 126380), (178, 112180), (284, 70310), (316, 63190), (355, 56248), (356, 56090), (395, 50552), (445, 44872), (568, 35155), (632, 31595), (710, 28124), (712, 28045), (790, 25276), (890, 22436), (1420, 14062), (1580, 12638), (1780, 11218), (2840, 7031), (3160, 6319), (3560, 5609)]