19780360

素因数分解:

$2^3\times 5^1\times {\mathrm{499}}^1\times {\mathrm{991}}^1$

素因数の和:1501

約数の個数: 32

約数和(自身を含む): 44640000

約数和(自身を除く): 24859640

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 499, 991, 998, 1982, 1996, 2495, 3964, 3992, 4955, 4990, 7928, 9910, 9980, 19820, 19960, 39640, 494509, 989018, 1978036, 2472545, 3956072, 4945090, 9890180, 19780360]

約数ペア:

[(1, 19780360), (2, 9890180), (4, 4945090), (5, 3956072), (8, 2472545), (10, 1978036), (20, 989018), (40, 494509), (499, 39640), (991, 19960), (998, 19820), (1982, 9980), (1996, 9910), (2495, 7928), (3964, 4990), (3992, 4955)]