21278090

素因数分解:

$2^1\times 5^1\times {\mathrm{31}}^1\times {\mathrm{68639}}^1$

素因数の和:68677

約数の個数: 16

約数和(自身を含む): 39536640

約数和(自身を除く): 18258550

約数列:

[1, 2, 5, 10, 31, 62, 155, 310, 68639, 137278, 343195, 686390, 2127809, 4255618, 10639045, 21278090]

約数ペア:

[(1, 21278090), (2, 10639045), (5, 4255618), (10, 2127809), (31, 686390), (62, 343195), (155, 137278), (310, 68639)]