21287780

素因数分解:

$2^2\times 5^1\times {\mathrm{61}}^1\times {\mathrm{17449}}^1$

素因数の和:17519

約数の個数: 24

約数和(自身を含む): 45439800

約数和(自身を除く): 24152020

約数列:

[1, 2, 4, 5, 10, 20, 61, 122, 244, 305, 610, 1220, 17449, 34898, 69796, 87245, 174490, 348980, 1064389, 2128778, 4257556, 5321945, 10643890, 21287780]

約数ペア:

[(1, 21287780), (2, 10643890), (4, 5321945), (5, 4257556), (10, 2128778), (20, 1064389), (61, 348980), (122, 174490), (244, 87245), (305, 69796), (610, 34898), (1220, 17449)]