21178820

素因数分解:

$2^2\times 5^1\times {\mathrm{13}}^1\times {\mathrm{81457}}^1$

素因数の和:81479

約数の個数: 24

約数和(自身を含む): 47897304

約数和(自身を除く): 26718484

約数列:

[1, 2, 4, 5, 10, 13, 20, 26, 52, 65, 130, 260, 81457, 162914, 325828, 407285, 814570, 1058941, 1629140, 2117882, 4235764, 5294705, 10589410, 21178820]

約数ペア:

[(1, 21178820), (2, 10589410), (4, 5294705), (5, 4235764), (10, 2117882), (13, 1629140), (20, 1058941), (26, 814570), (52, 407285), (65, 325828), (130, 162914), (260, 81457)]