21456940

素因数分解:

$2^2\times 5^1\times {\mathrm{41}}^1\times {\mathrm{137}}^1\times {\mathrm{191}}^1$

素因数の和:378

約数の個数: 48

約数和(自身を含む): 46738944

約数和(自身を除く): 25282004

約数列:

[1, 2, 4, 5, 10, 20, 41, 82, 137, 164, 191, 205, 274, 382, 410, 548, 685, 764, 820, 955, 1370, 1910, 2740, 3820, 5617, 7831, 11234, 15662, 22468, 26167, 28085, 31324, 39155, 52334, 56170, 78310, 104668, 112340, 130835, 156620, 261670, 523340, 1072847, 2145694, 4291388, 5364235, 10728470, 21456940]

約数ペア:

[(1, 21456940), (2, 10728470), (4, 5364235), (5, 4291388), (10, 2145694), (20, 1072847), (41, 523340), (82, 261670), (137, 156620), (164, 130835), (191, 112340), (205, 104668), (274, 78310), (382, 56170), (410, 52334), (548, 39155), (685, 31324), (764, 28085), (820, 26167), (955, 22468), (1370, 15662), (1910, 11234), (2740, 7831), (3820, 5617)]