21390775

素因数分解:

$5^2\times 7^1\times {\mathrm{31}}^1\times {\mathrm{3943}}^1$

素因数の和:3991

約数の個数: 24

約数和(自身を含む): 31299584

約数和(自身を除く): 9908809

約数列:

[1, 5, 7, 25, 31, 35, 155, 175, 217, 775, 1085, 3943, 5425, 19715, 27601, 98575, 122233, 138005, 611165, 690025, 855631, 3055825, 4278155, 21390775]

約数ペア:

[(1, 21390775), (5, 4278155), (7, 3055825), (25, 855631), (31, 690025), (35, 611165), (155, 138005), (175, 122233), (217, 98575), (775, 27601), (1085, 19715), (3943, 5425)]