21991221

素因数分解:

$3^2\times 7^1\times {\mathrm{103}}^1\times {\mathrm{3389}}^1$

素因数の和:3505

約数の個数: 24

約数和(自身を含む): 36666240

約数和(自身を除く): 14675019

約数列:

[1, 3, 7, 9, 21, 63, 103, 309, 721, 927, 2163, 3389, 6489, 10167, 23723, 30501, 71169, 213507, 349067, 1047201, 2443469, 3141603, 7330407, 21991221]

約数ペア:

[(1, 21991221), (3, 7330407), (7, 3141603), (9, 2443469), (21, 1047201), (63, 349067), (103, 213507), (309, 71169), (721, 30501), (927, 23723), (2163, 10167), (3389, 6489)]