20991685

素因数分解:

$5^1\times {\mathrm{11}}^2\times {\mathrm{13}}^1\times {\mathrm{17}}^1\times {\mathrm{157}}^1$

素因数の和:214

約数の個数: 48

約数和(自身を含む): 31773168

約数和(自身を除く): 10781483

約数列:

[1, 5, 11, 13, 17, 55, 65, 85, 121, 143, 157, 187, 221, 605, 715, 785, 935, 1105, 1573, 1727, 2041, 2057, 2431, 2669, 7865, 8635, 10205, 10285, 12155, 13345, 18997, 22451, 26741, 29359, 34697, 94985, 112255, 133705, 146795, 173485, 246961, 322949, 381667, 1234805, 1614745, 1908335, 4198337, 20991685]

約数ペア:

[(1, 20991685), (5, 4198337), (11, 1908335), (13, 1614745), (17, 1234805), (55, 381667), (65, 322949), (85, 246961), (121, 173485), (143, 146795), (157, 133705), (187, 112255), (221, 94985), (605, 34697), (715, 29359), (785, 26741), (935, 22451), (1105, 18997), (1573, 13345), (1727, 12155), (2041, 10285), (2057, 10205), (2431, 8635), (2669, 7865)]