21780213

素因数分解:

$3^1\times 7^1\times {\mathrm{13}}^2\times {\mathrm{17}}^1\times {\mathrm{19}}^2$

素因数の和:91

約数の個数: 72

約数和(自身を含む): 40160448

約数和(自身を除く): 18380235

約数列:

[1, 3, 7, 13, 17, 19, 21, 39, 51, 57, 91, 119, 133, 169, 221, 247, 273, 323, 357, 361, 399, 507, 663, 741, 969, 1083, 1183, 1547, 1729, 2261, 2527, 2873, 3211, 3549, 4199, 4641, 4693, 5187, 6137, 6783, 7581, 8619, 9633, 12597, 14079, 18411, 20111, 22477, 29393, 32851, 42959, 54587, 60333, 61009, 67431, 79781, 88179, 98553, 128877, 163761, 183027, 239343, 382109, 427063, 558467, 1037153, 1146327, 1281189, 1675401, 3111459, 7260071, 21780213]

約数ペア:

[(1, 21780213), (3, 7260071), (7, 3111459), (13, 1675401), (17, 1281189), (19, 1146327), (21, 1037153), (39, 558467), (51, 427063), (57, 382109), (91, 239343), (119, 183027), (133, 163761), (169, 128877), (221, 98553), (247, 88179), (273, 79781), (323, 67431), (357, 61009), (361, 60333), (399, 54587), (507, 42959), (663, 32851), (741, 29393), (969, 22477), (1083, 20111), (1183, 18411), (1547, 14079), (1729, 12597), (2261, 9633), (2527, 8619), (2873, 7581), (3211, 6783), (3549, 6137), (4199, 5187), (4641, 4693)]