21387961

素因数分解:

$7^2\times {\mathrm{37}}^1\times {\mathrm{47}}^1\times {\mathrm{251}}^1$

素因数の和:349

約数の個数: 24

約数和(自身を含む): 26199936

約数和(自身を除く): 4811975

約数列:

[1, 7, 37, 47, 49, 251, 259, 329, 1739, 1757, 1813, 2303, 9287, 11797, 12173, 12299, 65009, 82579, 85211, 436489, 455063, 578053, 3055423, 21387961]

約数ペア:

[(1, 21387961), (7, 3055423), (37, 578053), (47, 455063), (49, 436489), (251, 85211), (259, 82579), (329, 65009), (1739, 12299), (1757, 12173), (1813, 11797), (2303, 9287)]