21721640

素因数分解:

$2^3\times 5^1\times {\mathrm{257}}^1\times {\mathrm{2113}}^1$

素因数の和:2381

約数の個数: 32

約数和(自身を含む): 49087080

約数和(自身を除く): 27365440

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 257, 514, 1028, 1285, 2056, 2113, 2570, 4226, 5140, 8452, 10280, 10565, 16904, 21130, 42260, 84520, 543041, 1086082, 2172164, 2715205, 4344328, 5430410, 10860820, 21721640]

約数ペア:

[(1, 21721640), (2, 10860820), (4, 5430410), (5, 4344328), (8, 2715205), (10, 2172164), (20, 1086082), (40, 543041), (257, 84520), (514, 42260), (1028, 21130), (1285, 16904), (2056, 10565), (2113, 10280), (2570, 8452), (4226, 5140)]