20979980

素因数分解:

$2^2\times 5^1\times 7^1\times {\mathrm{277}}^1\times {\mathrm{541}}^1$

素因数の和:834

約数の個数: 48

約数和(自身を含む): 50627136

約数和(自身を除く): 29647156

約数列:

[1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140, 277, 541, 554, 1082, 1108, 1385, 1939, 2164, 2705, 2770, 3787, 3878, 5410, 5540, 7574, 7756, 9695, 10820, 15148, 18935, 19390, 37870, 38780, 75740, 149857, 299714, 599428, 749285, 1048999, 1498570, 2097998, 2997140, 4195996, 5244995, 10489990, 20979980]

約数ペア:

[(1, 20979980), (2, 10489990), (4, 5244995), (5, 4195996), (7, 2997140), (10, 2097998), (14, 1498570), (20, 1048999), (28, 749285), (35, 599428), (70, 299714), (140, 149857), (277, 75740), (541, 38780), (554, 37870), (1082, 19390), (1108, 18935), (1385, 15148), (1939, 10820), (2164, 9695), (2705, 7756), (2770, 7574), (3787, 5540), (3878, 5410)]