21075640

素因数分解:

$2^3\times 5^1\times {\mathrm{41}}^1\times {\mathrm{71}}^1\times {\mathrm{181}}^1$

素因数の和:304

約数の個数: 64

約数和(自身を含む): 49533120

約数和(自身を除く): 28457480

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 41, 71, 82, 142, 164, 181, 205, 284, 328, 355, 362, 410, 568, 710, 724, 820, 905, 1420, 1448, 1640, 1810, 2840, 2911, 3620, 5822, 7240, 7421, 11644, 12851, 14555, 14842, 23288, 25702, 29110, 29684, 37105, 51404, 58220, 59368, 64255, 74210, 102808, 116440, 128510, 148420, 257020, 296840, 514040, 526891, 1053782, 2107564, 2634455, 4215128, 5268910, 10537820, 21075640]

約数ペア:

[(1, 21075640), (2, 10537820), (4, 5268910), (5, 4215128), (8, 2634455), (10, 2107564), (20, 1053782), (40, 526891), (41, 514040), (71, 296840), (82, 257020), (142, 148420), (164, 128510), (181, 116440), (205, 102808), (284, 74210), (328, 64255), (355, 59368), (362, 58220), (410, 51404), (568, 37105), (710, 29684), (724, 29110), (820, 25702), (905, 23288), (1420, 14842), (1448, 14555), (1640, 12851), (1810, 11644), (2840, 7421), (2911, 7240), (3620, 5822)]