21397780

素因数分解:

$2^2\times 5^1\times {\mathrm{491}}^1\times {\mathrm{2179}}^1$

素因数の和:2679

約数の個数: 24

約数和(自身を含む): 45047520

約数和(自身を除く): 23649740

約数列:

[1, 2, 4, 5, 10, 20, 491, 982, 1964, 2179, 2455, 4358, 4910, 8716, 9820, 10895, 21790, 43580, 1069889, 2139778, 4279556, 5349445, 10698890, 21397780]

約数ペア:

[(1, 21397780), (2, 10698890), (4, 5349445), (5, 4279556), (10, 2139778), (20, 1069889), (491, 43580), (982, 21790), (1964, 10895), (2179, 9820), (2455, 8716), (4358, 4910)]