20991555

素因数分解:

$3^6\times 5^1\times {\mathrm{13}}^1\times {\mathrm{443}}^1$

素因数の和:479

約数の個数: 56

約数和(自身を含む): 40764528

約数和(自身を除く): 19772973

約数列:

[1, 3, 5, 9, 13, 15, 27, 39, 45, 65, 81, 117, 135, 195, 243, 351, 405, 443, 585, 729, 1053, 1215, 1329, 1755, 2215, 3159, 3645, 3987, 5265, 5759, 6645, 9477, 11961, 15795, 17277, 19935, 28795, 35883, 47385, 51831, 59805, 86385, 107649, 155493, 179415, 259155, 322947, 466479, 538245, 777465, 1399437, 1614735, 2332395, 4198311, 6997185, 20991555]

約数ペア:

[(1, 20991555), (3, 6997185), (5, 4198311), (9, 2332395), (13, 1614735), (15, 1399437), (27, 777465), (39, 538245), (45, 466479), (65, 322947), (81, 259155), (117, 179415), (135, 155493), (195, 107649), (243, 86385), (351, 59805), (405, 51831), (443, 47385), (585, 35883), (729, 28795), (1053, 19935), (1215, 17277), (1329, 15795), (1755, 11961), (2215, 9477), (3159, 6645), (3645, 5759), (3987, 5265)]