21381987

素因数分解:

$3^1\times {\mathrm{11}}^1\times {\mathrm{157}}^1\times {\mathrm{4127}}^1$

素因数の和:4298

約数の個数: 16

約数和(自身を含む): 31306752

約数和(自身を除く): 9924765

約数列:

[1, 3, 11, 33, 157, 471, 1727, 4127, 5181, 12381, 45397, 136191, 647939, 1943817, 7127329, 21381987]

約数ペア:

[(1, 21381987), (3, 7127329), (11, 1943817), (33, 647939), (157, 136191), (471, 45397), (1727, 12381), (4127, 5181)]