19781905

素因数分解:

$5^1\times {\mathrm{11}}^1\times {\mathrm{13}}^1\times {\mathrm{73}}^1\times {\mathrm{379}}^1$

素因数の和:481

約数の個数: 32

約数和(自身を含む): 28344960

約数和(自身を除く): 8563055

約数列:

[1, 5, 11, 13, 55, 65, 73, 143, 365, 379, 715, 803, 949, 1895, 4015, 4169, 4745, 4927, 10439, 20845, 24635, 27667, 52195, 54197, 138335, 270985, 304337, 359671, 1521685, 1798355, 3956381, 19781905]

約数ペア:

[(1, 19781905), (5, 3956381), (11, 1798355), (13, 1521685), (55, 359671), (65, 304337), (73, 270985), (143, 138335), (365, 54197), (379, 52195), (715, 27667), (803, 24635), (949, 20845), (1895, 10439), (4015, 4927), (4169, 4745)]