21386781

素因数分解:

$3^3\times {\mathrm{13}}^2\times {\mathrm{43}}^1\times {\mathrm{109}}^1$

素因数の和:187

約数の個数: 48

約数和(自身を含む): 35428800

約数和(自身を除く): 14042019

約数列:

[1, 3, 9, 13, 27, 39, 43, 109, 117, 129, 169, 327, 351, 387, 507, 559, 981, 1161, 1417, 1521, 1677, 2943, 4251, 4563, 4687, 5031, 7267, 12753, 14061, 15093, 18421, 21801, 38259, 42183, 55263, 60931, 65403, 126549, 165789, 182793, 196209, 497367, 548379, 792103, 1645137, 2376309, 7128927, 21386781]

約数ペア:

[(1, 21386781), (3, 7128927), (9, 2376309), (13, 1645137), (27, 792103), (39, 548379), (43, 497367), (109, 196209), (117, 182793), (129, 165789), (169, 126549), (327, 65403), (351, 60931), (387, 55263), (507, 42183), (559, 38259), (981, 21801), (1161, 18421), (1417, 15093), (1521, 14061), (1677, 12753), (2943, 7267), (4251, 5031), (4563, 4687)]