21720475

素因数分解:

$5^2\times 7^3\times {\mathrm{17}}^1\times {\mathrm{149}}^1$

素因数の和:197

約数の個数: 48

約数和(自身を含む): 33480000

約数和(自身を除く): 11759525

約数列:

[1, 5, 7, 17, 25, 35, 49, 85, 119, 149, 175, 245, 343, 425, 595, 745, 833, 1043, 1225, 1715, 2533, 2975, 3725, 4165, 5215, 5831, 7301, 8575, 12665, 17731, 20825, 26075, 29155, 36505, 51107, 63325, 88655, 124117, 145775, 182525, 255535, 443275, 620585, 868819, 1277675, 3102925, 4344095, 21720475]

約数ペア:

[(1, 21720475), (5, 4344095), (7, 3102925), (17, 1277675), (25, 868819), (35, 620585), (49, 443275), (85, 255535), (119, 182525), (149, 145775), (175, 124117), (245, 88655), (343, 63325), (425, 51107), (595, 36505), (745, 29155), (833, 26075), (1043, 20825), (1225, 17731), (1715, 12665), (2533, 8575), (2975, 7301), (3725, 5831), (4165, 5215)]