21120021

素因数分解:

$3^4\times {\mathrm{13}}^1\times {\mathrm{31}}^1\times {\mathrm{647}}^1$

素因数の和:703

約数の個数: 40

約数和(自身を含む): 35126784

約数和(自身を除く): 14006763

約数列:

[1, 3, 9, 13, 27, 31, 39, 81, 93, 117, 279, 351, 403, 647, 837, 1053, 1209, 1941, 2511, 3627, 5823, 8411, 10881, 17469, 20057, 25233, 32643, 52407, 60171, 75699, 180513, 227097, 260741, 541539, 681291, 782223, 1624617, 2346669, 7040007, 21120021]

約数ペア:

[(1, 21120021), (3, 7040007), (9, 2346669), (13, 1624617), (27, 782223), (31, 681291), (39, 541539), (81, 260741), (93, 227097), (117, 180513), (279, 75699), (351, 60171), (403, 52407), (647, 32643), (837, 25233), (1053, 20057), (1209, 17469), (1941, 10881), (2511, 8411), (3627, 5823)]