21991775

素因数分解:

$5^2\times {\mathrm{13}}^1\times {\mathrm{157}}^1\times {\mathrm{431}}^1$

素因数の和:611

約数の個数: 24

約数和(自身を含む): 29623104

約数和(自身を除く): 7631329

約数列:

[1, 5, 13, 25, 65, 157, 325, 431, 785, 2041, 2155, 3925, 5603, 10205, 10775, 28015, 51025, 67667, 140075, 338335, 879671, 1691675, 4398355, 21991775]

約数ペア:

[(1, 21991775), (5, 4398355), (13, 1691675), (25, 879671), (65, 338335), (157, 140075), (325, 67667), (431, 51025), (785, 28015), (2041, 10775), (2155, 10205), (3925, 5603)]