21027920

素因数分解:

$2^4\times 5^1\times {\mathrm{31}}^1\times {\mathrm{61}}^1\times {\mathrm{139}}^1$

素因数の和:244

約数の個数: 80

約数和(自身を含む): 51663360

約数和(自身を除く): 30635440

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 31, 40, 61, 62, 80, 122, 124, 139, 155, 244, 248, 278, 305, 310, 488, 496, 556, 610, 620, 695, 976, 1112, 1220, 1240, 1390, 1891, 2224, 2440, 2480, 2780, 3782, 4309, 4880, 5560, 7564, 8479, 8618, 9455, 11120, 15128, 16958, 17236, 18910, 21545, 30256, 33916, 34472, 37820, 42395, 43090, 67832, 68944, 75640, 84790, 86180, 135664, 151280, 169580, 172360, 262849, 339160, 344720, 525698, 678320, 1051396, 1314245, 2102792, 2628490, 4205584, 5256980, 10513960, 21027920]

約数ペア:

[(1, 21027920), (2, 10513960), (4, 5256980), (5, 4205584), (8, 2628490), (10, 2102792), (16, 1314245), (20, 1051396), (31, 678320), (40, 525698), (61, 344720), (62, 339160), (80, 262849), (122, 172360), (124, 169580), (139, 151280), (155, 135664), (244, 86180), (248, 84790), (278, 75640), (305, 68944), (310, 67832), (488, 43090), (496, 42395), (556, 37820), (610, 34472), (620, 33916), (695, 30256), (976, 21545), (1112, 18910), (1220, 17236), (1240, 16958), (1390, 15128), (1891, 11120), (2224, 9455), (2440, 8618), (2480, 8479), (2780, 7564), (3782, 5560), (4309, 4880)]