21981155

素因数分解:

$5^1\times 7^4\times {\mathrm{1831}}^1$

素因数の和:1864

約数の個数: 20

約数和(自身を含む): 30788592

約数和(自身を除く): 8807437

約数列:

[1, 5, 7, 35, 49, 245, 343, 1715, 1831, 2401, 9155, 12005, 12817, 64085, 89719, 448595, 628033, 3140165, 4396231, 21981155]

約数ペア:

[(1, 21981155), (5, 4396231), (7, 3140165), (35, 628033), (49, 448595), (245, 89719), (343, 64085), (1715, 12817), (1831, 12005), (2401, 9155)]