4000000

素因数分解:

$2^8\times 5^6$

素因数の和:46

約数の個数: 63

約数和(自身を含む): 9980341

約数和(自身を除く): 5980341

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 25, 32, 40, 50, 64, 80, 100, 125, 128, 160, 200, 250, 256, 320, 400, 500, 625, 640, 800, 1000, 1250, 1280, 1600, 2000, 2500, 3125, 3200, 4000, 5000, 6250, 6400, 8000, 10000, 12500, 15625, 16000, 20000, 25000, 31250, 32000, 40000, 50000, 62500, 80000, 100000, 125000, 160000, 200000, 250000, 400000, 500000, 800000, 1000000, 2000000, 4000000]

約数ペア:

[(1, 4000000), (2, 2000000), (4, 1000000), (5, 800000), (8, 500000), (10, 400000), (16, 250000), (20, 200000), (25, 160000), (32, 125000), (40, 100000), (50, 80000), (64, 62500), (80, 50000), (100, 40000), (125, 32000), (128, 31250), (160, 25000), (200, 20000), (250, 16000), (256, 15625), (320, 12500), (400, 10000), (500, 8000), (625, 6400), (640, 6250), (800, 5000), (1000, 4000), (1250, 3200), (1280, 3125), (1600, 2500)]