19901721

素因数分解:

$3^1\times 7^1\times {\mathrm{19}}^1\times {\mathrm{31}}^1\times {\mathrm{1609}}^1$

素因数の和:1669

約数の個数: 32

約数和(自身を含む): 32972800

約数和(自身を除く): 13071079

約数列:

[1, 3, 7, 19, 21, 31, 57, 93, 133, 217, 399, 589, 651, 1609, 1767, 4123, 4827, 11263, 12369, 30571, 33789, 49879, 91713, 149637, 213997, 349153, 641991, 947701, 1047459, 2843103, 6633907, 19901721]

約数ペア:

[(1, 19901721), (3, 6633907), (7, 2843103), (19, 1047459), (21, 947701), (31, 641991), (57, 349153), (93, 213997), (133, 149637), (217, 91713), (399, 49879), (589, 33789), (651, 30571), (1609, 12369), (1767, 11263), (4123, 4827)]