20402000

素因数分解:

$2^4\times 5^3\times {\mathrm{101}}^2$

素因数の和:225

約数の個数: 60

約数和(自身を含む): 49825308

約数和(自身を除く): 29423308

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 101, 125, 200, 202, 250, 400, 404, 500, 505, 808, 1000, 1010, 1616, 2000, 2020, 2525, 4040, 5050, 8080, 10100, 10201, 12625, 20200, 20402, 25250, 40400, 40804, 50500, 51005, 81608, 101000, 102010, 163216, 202000, 204020, 255025, 408040, 510050, 816080, 1020100, 1275125, 2040200, 2550250, 4080400, 5100500, 10201000, 20402000]

約数ペア:

[(1, 20402000), (2, 10201000), (4, 5100500), (5, 4080400), (8, 2550250), (10, 2040200), (16, 1275125), (20, 1020100), (25, 816080), (40, 510050), (50, 408040), (80, 255025), (100, 204020), (101, 202000), (125, 163216), (200, 102010), (202, 101000), (250, 81608), (400, 51005), (404, 50500), (500, 40804), (505, 40400), (808, 25250), (1000, 20402), (1010, 20200), (1616, 12625), (2000, 10201), (2020, 10100), (2525, 8080), (4040, 5050)]