21978760

素因数分解:

$2^3\times 5^1\times {\mathrm{71}}^2\times {\mathrm{109}}^1$

素因数の和:262

約数の個数: 48

約数和(自身を含む): 50618700

約数和(自身を除く): 28639940

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 71, 109, 142, 218, 284, 355, 436, 545, 568, 710, 872, 1090, 1420, 2180, 2840, 4360, 5041, 7739, 10082, 15478, 20164, 25205, 30956, 38695, 40328, 50410, 61912, 77390, 100820, 154780, 201640, 309560, 549469, 1098938, 2197876, 2747345, 4395752, 5494690, 10989380, 21978760]

約数ペア:

[(1, 21978760), (2, 10989380), (4, 5494690), (5, 4395752), (8, 2747345), (10, 2197876), (20, 1098938), (40, 549469), (71, 309560), (109, 201640), (142, 154780), (218, 100820), (284, 77390), (355, 61912), (436, 50410), (545, 40328), (568, 38695), (710, 30956), (872, 25205), (1090, 20164), (1420, 15478), (2180, 10082), (2840, 7739), (4360, 5041)]