21240005

素因数分解:

$5^1\times {\mathrm{19}}^1\times {\mathrm{47}}^1\times {\mathrm{67}}^1\times {\mathrm{71}}^1$

素因数の和:209

約数の個数: 32

約数和(自身を含む): 28200960

約数和(自身を除く): 6960955

約数列:

[1, 5, 19, 47, 67, 71, 95, 235, 335, 355, 893, 1273, 1349, 3149, 3337, 4465, 4757, 6365, 6745, 15745, 16685, 23785, 59831, 63403, 90383, 223579, 299155, 317015, 451915, 1117895, 4248001, 21240005]

約数ペア:

[(1, 21240005), (5, 4248001), (19, 1117895), (47, 451915), (67, 317015), (71, 299155), (95, 223579), (235, 90383), (335, 63403), (355, 59831), (893, 23785), (1273, 16685), (1349, 15745), (3149, 6745), (3337, 6365), (4465, 4757)]