21720321

素因数分解:

$3^2\times 7^1\times {\mathrm{109}}^1\times {\mathrm{3163}}^1$

素因数の和:3285

約数の個数: 24

約数和(自身を含む): 36196160

約数和(自身を除く): 14475839

約数列:

[1, 3, 7, 9, 21, 63, 109, 327, 763, 981, 2289, 3163, 6867, 9489, 22141, 28467, 66423, 199269, 344767, 1034301, 2413369, 3102903, 7240107, 21720321]

約数ペア:

[(1, 21720321), (3, 7240107), (7, 3102903), (9, 2413369), (21, 1034301), (63, 344767), (109, 199269), (327, 66423), (763, 28467), (981, 22141), (2289, 9489), (3163, 6867)]