20991551

素因数分解:

$7^2\times {\mathrm{53}}^1\times {\mathrm{59}}^1\times {\mathrm{137}}^1$

素因数の和:263

約数の個数: 24

約数和(自身を含む): 25485840

約数和(自身を除く): 4494289

約数列:

[1, 7, 49, 53, 59, 137, 371, 413, 959, 2597, 2891, 3127, 6713, 7261, 8083, 21889, 50827, 56581, 153223, 355789, 396067, 428399, 2998793, 20991551]

約数ペア:

[(1, 20991551), (7, 2998793), (49, 428399), (53, 396067), (59, 355789), (137, 153223), (371, 56581), (413, 50827), (959, 21889), (2597, 8083), (2891, 7261), (3127, 6713)]