21387985

素因数分解:

$5^1\times {\mathrm{31}}^1\times {\mathrm{43}}^1\times {\mathrm{3209}}^1$

素因数の和:3288

約数の個数: 16

約数和(自身を含む): 27118080

約数和(自身を除く): 5730095

約数列:

[1, 5, 31, 43, 155, 215, 1333, 3209, 6665, 16045, 99479, 137987, 497395, 689935, 4277597, 21387985]

約数ペア:

[(1, 21387985), (5, 4277597), (31, 689935), (43, 497395), (155, 137987), (215, 99479), (1333, 16045), (3209, 6665)]