21387980

素因数分解:

$2^2\times 5^1\times {\mathrm{109}}^1\times {\mathrm{9811}}^1$

素因数の和:9929

約数の個数: 24

約数和(自身を含む): 45331440

約数和(自身を除く): 23943460

約数列:

[1, 2, 4, 5, 10, 20, 109, 218, 436, 545, 1090, 2180, 9811, 19622, 39244, 49055, 98110, 196220, 1069399, 2138798, 4277596, 5346995, 10693990, 21387980]

約数ペア:

[(1, 21387980), (2, 10693990), (4, 5346995), (5, 4277596), (10, 2138798), (20, 1069399), (109, 196220), (218, 98110), (436, 49055), (545, 39244), (1090, 19622), (2180, 9811)]