21078385

素因数分解:

$5^1\times {\mathrm{17}}^1\times {\mathrm{43}}^1\times {\mathrm{73}}^1\times {\mathrm{79}}^1$

素因数の和:217

約数の個数: 32

約数和(自身を含む): 28131840

約数和(自身を除く): 7053455

約数列:

[1, 5, 17, 43, 73, 79, 85, 215, 365, 395, 731, 1241, 1343, 3139, 3397, 3655, 5767, 6205, 6715, 15695, 16985, 28835, 53363, 57749, 98039, 247981, 266815, 288745, 490195, 1239905, 4215677, 21078385]

約数ペア:

[(1, 21078385), (5, 4215677), (17, 1239905), (43, 490195), (73, 288745), (79, 266815), (85, 247981), (215, 98039), (365, 57749), (395, 53363), (731, 28835), (1241, 16985), (1343, 15695), (3139, 6715), (3397, 6205), (3655, 5767)]