21087905

素因数分解:

$5^1\times {\mathrm{17}}^1\times {\mathrm{31}}^1\times {\mathrm{53}}^1\times {\mathrm{151}}^1$

素因数の和:257

約数の個数: 32

約数和(自身を含む): 28366848

約数和(自身を除く): 7278943

約数列:

[1, 5, 17, 31, 53, 85, 151, 155, 265, 527, 755, 901, 1643, 2567, 2635, 4505, 4681, 8003, 8215, 12835, 23405, 27931, 40015, 79577, 136051, 139655, 248093, 397885, 680255, 1240465, 4217581, 21087905]

約数ペア:

[(1, 21087905), (5, 4217581), (17, 1240465), (31, 680255), (53, 397885), (85, 248093), (151, 139655), (155, 136051), (265, 79577), (527, 40015), (755, 27931), (901, 23405), (1643, 12835), (2567, 8215), (2635, 8003), (4505, 4681)]