19890871

素因数分解:

$7^1\times {\mathrm{11}}^1\times {\mathrm{13}}^1\times {\mathrm{31}}^1\times {\mathrm{641}}^1$

素因数の和:703

約数の個数: 32

約数和(自身を含む): 27611136

約数和(自身を除く): 7720265

約数列:

[1, 7, 11, 13, 31, 77, 91, 143, 217, 341, 403, 641, 1001, 2387, 2821, 4433, 4487, 7051, 8333, 19871, 31031, 49357, 58331, 91663, 139097, 218581, 258323, 641641, 1530067, 1808261, 2841553, 19890871]

約数ペア:

[(1, 19890871), (7, 2841553), (11, 1808261), (13, 1530067), (31, 641641), (77, 258323), (91, 218581), (143, 139097), (217, 91663), (341, 58331), (403, 49357), (641, 31031), (1001, 19871), (2387, 8333), (2821, 7051), (4433, 4487)]