21720980

素因数分解:

$2^2\times 5^1\times {\mathrm{41}}^1\times {\mathrm{26489}}^1$

素因数の和:26539

約数の個数: 24

約数和(自身を含む): 46728360

約数和(自身を除く): 25007380

約数列:

[1, 2, 4, 5, 10, 20, 41, 82, 164, 205, 410, 820, 26489, 52978, 105956, 132445, 264890, 529780, 1086049, 2172098, 4344196, 5430245, 10860490, 21720980]

約数ペア:

[(1, 21720980), (2, 10860490), (4, 5430245), (5, 4344196), (10, 2172098), (20, 1086049), (41, 529780), (82, 264890), (164, 132445), (205, 105956), (410, 52978), (820, 26489)]