639680

素因数分解:

$2^6\times 5^1\times {\mathrm{1999}}^1$

素因数の和:2016

約数の個数: 28

約数和(自身を含む): 1524000

約数和(自身を除く): 884320

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 1999, 3998, 7996, 9995, 15992, 19990, 31984, 39980, 63968, 79960, 127936, 159920, 319840, 639680]

約数ペア:

[(1, 639680), (2, 319840), (4, 159920), (5, 127936), (8, 79960), (10, 63968), (16, 39980), (20, 31984), (32, 19990), (40, 15992), (64, 9995), (80, 7996), (160, 3998), (320, 1999)]