21519905

素因数分解:

$5^1\times {\mathrm{11}}^1\times {\mathrm{521}}^1\times {\mathrm{751}}^1$

素因数の和:1288

約数の個数: 16

約数和(自身を含む): 28263168

約数和(自身を除く): 6743263

約数列:

[1, 5, 11, 55, 521, 751, 2605, 3755, 5731, 8261, 28655, 41305, 391271, 1956355, 4303981, 21519905]

約数ペア:

[(1, 21519905), (5, 4303981), (11, 1956355), (55, 391271), (521, 41305), (751, 28655), (2605, 8261), (3755, 5731)]