20641640

素因数分解:

$2^3\times 5^1\times {\mathrm{491}}^1\times {\mathrm{1051}}^1$

素因数の和:1553

約数の個数: 32

約数和(自身を含む): 46582560

約数和(自身を除く): 25940920

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 491, 982, 1051, 1964, 2102, 2455, 3928, 4204, 4910, 5255, 8408, 9820, 10510, 19640, 21020, 42040, 516041, 1032082, 2064164, 2580205, 4128328, 5160410, 10320820, 20641640]

約数ペア:

[(1, 20641640), (2, 10320820), (4, 5160410), (5, 4128328), (8, 2580205), (10, 2064164), (20, 1032082), (40, 516041), (491, 42040), (982, 21020), (1051, 19640), (1964, 10510), (2102, 9820), (2455, 8408), (3928, 5255), (4204, 4910)]