21780145

素因数分解:

$5^1\times {\mathrm{17}}^1\times {\mathrm{43}}^1\times {\mathrm{59}}^1\times {\mathrm{101}}^1$

素因数の和:225

約数の個数: 32

約数和(自身を含む): 29082240

約数和(自身を除く): 7302095

約数列:

[1, 5, 17, 43, 59, 85, 101, 215, 295, 505, 731, 1003, 1717, 2537, 3655, 4343, 5015, 5959, 8585, 12685, 21715, 29795, 43129, 73831, 101303, 215645, 256237, 369155, 506515, 1281185, 4356029, 21780145]

約数ペア:

[(1, 21780145), (5, 4356029), (17, 1281185), (43, 506515), (59, 369155), (85, 256237), (101, 215645), (215, 101303), (295, 73831), (505, 43129), (731, 29795), (1003, 21715), (1717, 12685), (2537, 8585), (3655, 5959), (4343, 5015)]