19977980

素因数分解:

$2^2\times 5^1\times {\mathrm{11}}^1\times {\mathrm{71}}^1\times {\mathrm{1279}}^1$

素因数の和:1370

約数の個数: 48

約数和(自身を含む): 46448640

約数和(自身を除く): 26470660

約数列:

[1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 71, 110, 142, 220, 284, 355, 710, 781, 1279, 1420, 1562, 2558, 3124, 3905, 5116, 6395, 7810, 12790, 14069, 15620, 25580, 28138, 56276, 70345, 90809, 140690, 181618, 281380, 363236, 454045, 908090, 998899, 1816180, 1997798, 3995596, 4994495, 9988990, 19977980]

約数ペア:

[(1, 19977980), (2, 9988990), (4, 4994495), (5, 3995596), (10, 1997798), (11, 1816180), (20, 998899), (22, 908090), (44, 454045), (55, 363236), (71, 281380), (110, 181618), (142, 140690), (220, 90809), (284, 70345), (355, 56276), (710, 28138), (781, 25580), (1279, 15620), (1420, 14069), (1562, 12790), (2558, 7810), (3124, 6395), (3905, 5116)]