21278840

素因数分解:

$2^3\times 5^1\times {\mathrm{11}}^1\times {\mathrm{137}}^1\times {\mathrm{353}}^1$

素因数の和:512

約数の個数: 64

約数和(自身を含む): 52760160

約数和(自身を除く): 31481320

約数列:

[1, 2, 4, 5, 8, 10, 11, 20, 22, 40, 44, 55, 88, 110, 137, 220, 274, 353, 440, 548, 685, 706, 1096, 1370, 1412, 1507, 1765, 2740, 2824, 3014, 3530, 3883, 5480, 6028, 7060, 7535, 7766, 12056, 14120, 15070, 15532, 19415, 30140, 31064, 38830, 48361, 60280, 77660, 96722, 155320, 193444, 241805, 386888, 483610, 531971, 967220, 1063942, 1934440, 2127884, 2659855, 4255768, 5319710, 10639420, 21278840]

約数ペア:

[(1, 21278840), (2, 10639420), (4, 5319710), (5, 4255768), (8, 2659855), (10, 2127884), (11, 1934440), (20, 1063942), (22, 967220), (40, 531971), (44, 483610), (55, 386888), (88, 241805), (110, 193444), (137, 155320), (220, 96722), (274, 77660), (353, 60280), (440, 48361), (548, 38830), (685, 31064), (706, 30140), (1096, 19415), (1370, 15532), (1412, 15070), (1507, 14120), (1765, 12056), (2740, 7766), (2824, 7535), (3014, 7060), (3530, 6028), (3883, 5480)]