20991971

素因数分解:

$7^1\times {\mathrm{11}}^1\times {\mathrm{13}}^1\times {\mathrm{67}}^1\times {\mathrm{313}}^1$

素因数の和:411

約数の個数: 32

約数和(自身を含む): 28697088

約数和(自身を除く): 7705117

約数列:

[1, 7, 11, 13, 67, 77, 91, 143, 313, 469, 737, 871, 1001, 2191, 3443, 4069, 5159, 6097, 9581, 20971, 24101, 28483, 44759, 67067, 146797, 230681, 272623, 313313, 1614767, 1908361, 2998853, 20991971]

約数ペア:

[(1, 20991971), (7, 2998853), (11, 1908361), (13, 1614767), (67, 313313), (77, 272623), (91, 230681), (143, 146797), (313, 67067), (469, 44759), (737, 28483), (871, 24101), (1001, 20971), (2191, 9581), (3443, 6097), (4069, 5159)]