21178521

素因数分解:

$3^2\times 7^1\times {\mathrm{13}}^1\times {\mathrm{19}}^1\times {\mathrm{1361}}^1$

素因数の和:1406

約数の個数: 48

約数和(自身を含む): 39661440

約数和(自身を除く): 18482919

約数列:

[1, 3, 7, 9, 13, 19, 21, 39, 57, 63, 91, 117, 133, 171, 247, 273, 399, 741, 819, 1197, 1361, 1729, 2223, 4083, 5187, 9527, 12249, 15561, 17693, 25859, 28581, 53079, 77577, 85743, 123851, 159237, 181013, 232731, 336167, 371553, 543039, 1008501, 1114659, 1629117, 2353169, 3025503, 7059507, 21178521]

約数ペア:

[(1, 21178521), (3, 7059507), (7, 3025503), (9, 2353169), (13, 1629117), (19, 1114659), (21, 1008501), (39, 543039), (57, 371553), (63, 336167), (91, 232731), (117, 181013), (133, 159237), (171, 123851), (247, 85743), (273, 77577), (399, 53079), (741, 28581), (819, 25859), (1197, 17693), (1361, 15561), (1729, 12249), (2223, 9527), (4083, 5187)]