20991515

素因数分解:

$5^1\times {\mathrm{17}}^2\times {\mathrm{73}}^1\times {\mathrm{199}}^1$

素因数の和:311

約数の個数: 24

約数和(自身を含む): 27261600

約数和(自身を除く): 6270085

約数列:

[1, 5, 17, 73, 85, 199, 289, 365, 995, 1241, 1445, 3383, 6205, 14527, 16915, 21097, 57511, 72635, 105485, 246959, 287555, 1234795, 4198303, 20991515]

約数ペア:

[(1, 20991515), (5, 4198303), (17, 1234795), (73, 287555), (85, 246959), (199, 105485), (289, 72635), (365, 57511), (995, 21097), (1241, 16915), (1445, 14527), (3383, 6205)]