21990787

素因数分解:

$7^1\times {\mathrm{13}}^2\times {\mathrm{29}}^1\times {\mathrm{641}}^1$

素因数の和:703

約数の個数: 24

約数和(自身を含む): 28196640

約数和(自身を除く): 6205853

約数列:

[1, 7, 13, 29, 91, 169, 203, 377, 641, 1183, 2639, 4487, 4901, 8333, 18589, 34307, 58331, 108329, 130123, 241657, 758303, 1691599, 3141541, 21990787]

約数ペア:

[(1, 21990787), (7, 3141541), (13, 1691599), (29, 758303), (91, 241657), (169, 130123), (203, 108329), (377, 58331), (641, 34307), (1183, 18589), (2639, 8333), (4487, 4901)]