21287205

素因数分解:

$3^4\times 5^1\times {\mathrm{52561}}^1$

素因数の和:52578

約数の個数: 20

約数和(自身を含む): 38160012

約数和(自身を除く): 16872807

約数列:

[1, 3, 5, 9, 15, 27, 45, 81, 135, 405, 52561, 157683, 262805, 473049, 788415, 1419147, 2365245, 4257441, 7095735, 21287205]

約数ペア:

[(1, 21287205), (3, 7095735), (5, 4257441), (9, 2365245), (15, 1419147), (27, 788415), (45, 473049), (81, 262805), (135, 157683), (405, 52561)]