19801405

素因数分解:

$5^1\times {\mathrm{13}}^1\times {\mathrm{31}}^2\times {\mathrm{317}}^1$

素因数の和:397

約数の個数: 24

約数和(自身を含む): 26525016

約数和(自身を除く): 6723611

約数列:

[1, 5, 13, 31, 65, 155, 317, 403, 961, 1585, 2015, 4121, 4805, 9827, 12493, 20605, 49135, 62465, 127751, 304637, 638755, 1523185, 3960281, 19801405]

約数ペア:

[(1, 19801405), (5, 3960281), (13, 1523185), (31, 638755), (65, 304637), (155, 127751), (317, 62465), (403, 49135), (961, 20605), (1585, 12493), (2015, 9827), (4121, 4805)]