21505220

素因数分解:

$2^2\times 5^1\times {\mathrm{11}}^1\times {\mathrm{239}}^1\times {\mathrm{409}}^1$

素因数の和:668

約数の個数: 48

約数和(自身を含む): 49593600

約数和(自身を除く): 28088380

約数列:

[1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220, 239, 409, 478, 818, 956, 1195, 1636, 2045, 2390, 2629, 4090, 4499, 4780, 5258, 8180, 8998, 10516, 13145, 17996, 22495, 26290, 44990, 52580, 89980, 97751, 195502, 391004, 488755, 977510, 1075261, 1955020, 2150522, 4301044, 5376305, 10752610, 21505220]

約数ペア:

[(1, 21505220), (2, 10752610), (4, 5376305), (5, 4301044), (10, 2150522), (11, 1955020), (20, 1075261), (22, 977510), (44, 488755), (55, 391004), (110, 195502), (220, 97751), (239, 89980), (409, 52580), (478, 44990), (818, 26290), (956, 22495), (1195, 17996), (1636, 13145), (2045, 10516), (2390, 8998), (2629, 8180), (4090, 5258), (4499, 4780)]