19900120

素因数分解:

$2^3\times 5^1\times {\mathrm{499}}^1\times {\mathrm{997}}^1$

素因数の和:1507

約数の個数: 32

約数和(自身を含む): 44910000

約数和(自身を除く): 25009880

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 499, 997, 998, 1994, 1996, 2495, 3988, 3992, 4985, 4990, 7976, 9970, 9980, 19940, 19960, 39880, 497503, 995006, 1990012, 2487515, 3980024, 4975030, 9950060, 19900120]

約数ペア:

[(1, 19900120), (2, 9950060), (4, 4975030), (5, 3980024), (8, 2487515), (10, 1990012), (20, 995006), (40, 497503), (499, 39880), (997, 19960), (998, 19940), (1994, 9980), (1996, 9970), (2495, 7976), (3988, 4990), (3992, 4985)]