640400

素因数分解:

$2^4\times 5^2\times {\mathrm{1601}}^1$

素因数の和:1619

約数の個数: 30

約数和(自身を含む): 1539522

約数和(自身を除く): 899122

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400, 1601, 3202, 6404, 8005, 12808, 16010, 25616, 32020, 40025, 64040, 80050, 128080, 160100, 320200, 640400]

約数ペア:

[(1, 640400), (2, 320200), (4, 160100), (5, 128080), (8, 80050), (10, 64040), (16, 40025), (20, 32020), (25, 25616), (40, 16010), (50, 12808), (80, 8005), (100, 6404), (200, 3202), (400, 1601)]