20560000

素因数分解:

$2^7\times 5^4\times {\mathrm{257}}^1$

素因数の和:291

約数の個数: 80

約数和(自身を含む): 51381990

約数和(自身を除く): 30821990

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 25, 32, 40, 50, 64, 80, 100, 125, 128, 160, 200, 250, 257, 320, 400, 500, 514, 625, 640, 800, 1000, 1028, 1250, 1285, 1600, 2000, 2056, 2500, 2570, 3200, 4000, 4112, 5000, 5140, 6425, 8000, 8224, 10000, 10280, 12850, 16000, 16448, 20000, 20560, 25700, 32125, 32896, 40000, 41120, 51400, 64250, 80000, 82240, 102800, 128500, 160625, 164480, 205600, 257000, 321250, 411200, 514000, 642500, 822400, 1028000, 1285000, 2056000, 2570000, 4112000, 5140000, 10280000, 20560000]

約数ペア:

[(1, 20560000), (2, 10280000), (4, 5140000), (5, 4112000), (8, 2570000), (10, 2056000), (16, 1285000), (20, 1028000), (25, 822400), (32, 642500), (40, 514000), (50, 411200), (64, 321250), (80, 257000), (100, 205600), (125, 164480), (128, 160625), (160, 128500), (200, 102800), (250, 82240), (257, 80000), (320, 64250), (400, 51400), (500, 41120), (514, 40000), (625, 32896), (640, 32125), (800, 25700), (1000, 20560), (1028, 20000), (1250, 16448), (1285, 16000), (1600, 12850), (2000, 10280), (2056, 10000), (2500, 8224), (2570, 8000), (3200, 6425), (4000, 5140), (4112, 5000)]