20990991

素因数分解:

$3^1\times 7^1\times {\mathrm{19}}^1\times {\mathrm{52609}}^1$

素因数の和:52638

約数の個数: 16

約数和(自身を含む): 33670400

約数和(自身を除く): 12679409

約数列:

[1, 3, 7, 19, 21, 57, 133, 399, 52609, 157827, 368263, 999571, 1104789, 2998713, 6996997, 20990991]

約数ペア:

[(1, 20990991), (3, 6996997), (7, 2998713), (19, 1104789), (21, 999571), (57, 368263), (133, 157827), (399, 52609)]