21720181

素因数分解:

$7^2\times {\mathrm{31}}^1\times {\mathrm{79}}^1\times {\mathrm{181}}^1$

素因数の和:305

約数の個数: 24

約数和(自身を含む): 26557440

約数和(自身を除く): 4837259

約数列:

[1, 7, 31, 49, 79, 181, 217, 553, 1267, 1519, 2449, 3871, 5611, 8869, 14299, 17143, 39277, 100093, 120001, 274939, 443269, 700651, 3102883, 21720181]

約数ペア:

[(1, 21720181), (7, 3102883), (31, 700651), (49, 443269), (79, 274939), (181, 120001), (217, 100093), (553, 39277), (1267, 17143), (1519, 14299), (2449, 8869), (3871, 5611)]