20405905

素因数分解:

$5^1\times {\mathrm{13}}^2\times {\mathrm{19}}^1\times {\mathrm{31}}^1\times {\mathrm{41}}^1$

素因数の和:122

約数の個数: 48

約数和(自身を含む): 29514240

約数和(自身を除く): 9108335

約数列:

[1, 5, 13, 19, 31, 41, 65, 95, 155, 169, 205, 247, 403, 533, 589, 779, 845, 1235, 1271, 2015, 2665, 2945, 3211, 3895, 5239, 6355, 6929, 7657, 10127, 16055, 16523, 24149, 26195, 34645, 38285, 50635, 82615, 99541, 120745, 131651, 214799, 313937, 497705, 658255, 1073995, 1569685, 4081181, 20405905]

約数ペア:

[(1, 20405905), (5, 4081181), (13, 1569685), (19, 1073995), (31, 658255), (41, 497705), (65, 313937), (95, 214799), (155, 131651), (169, 120745), (205, 99541), (247, 82615), (403, 50635), (533, 38285), (589, 34645), (779, 26195), (845, 24149), (1235, 16523), (1271, 16055), (2015, 10127), (2665, 7657), (2945, 6929), (3211, 6355), (3895, 5239)]