21781431

素因数分解:

$3^2\times 7^2\times {\mathrm{49391}}^1$

素因数の和:49411

約数の個数: 18

約数和(自身を含む): 36599472

約数和(自身を除く): 14818041

約数列:

[1, 3, 7, 9, 21, 49, 63, 147, 441, 49391, 148173, 345737, 444519, 1037211, 2420159, 3111633, 7260477, 21781431]

約数ペア:

[(1, 21781431), (3, 7260477), (7, 3111633), (9, 2420159), (21, 1037211), (49, 444519), (63, 345737), (147, 148173), (441, 49391)]