20991355

素因数分解:

$5^1\times 7^2\times {\mathrm{11}}^1\times {\mathrm{7789}}^1$

素因数の和:7819

約数の個数: 24

約数和(自身を含む): 31970160

約数和(自身を除く): 10978805

約数列:

[1, 5, 7, 11, 35, 49, 55, 77, 245, 385, 539, 2695, 7789, 38945, 54523, 85679, 272615, 381661, 428395, 599753, 1908305, 2998765, 4198271, 20991355]

約数ペア:

[(1, 20991355), (5, 4198271), (7, 2998765), (11, 1908305), (35, 599753), (49, 428395), (55, 381661), (77, 272615), (245, 85679), (385, 54523), (539, 38945), (2695, 7789)]