21503920

素因数分解:

$2^4\times 5^1\times {\mathrm{389}}^1\times {\mathrm{691}}^1$

素因数の和:1093

約数の個数: 40

約数和(自身を含む): 50197680

約数和(自身を除く): 28693760

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 40, 80, 389, 691, 778, 1382, 1556, 1945, 2764, 3112, 3455, 3890, 5528, 6224, 6910, 7780, 11056, 13820, 15560, 27640, 31120, 55280, 268799, 537598, 1075196, 1343995, 2150392, 2687990, 4300784, 5375980, 10751960, 21503920]

約数ペア:

[(1, 21503920), (2, 10751960), (4, 5375980), (5, 4300784), (8, 2687990), (10, 2150392), (16, 1343995), (20, 1075196), (40, 537598), (80, 268799), (389, 55280), (691, 31120), (778, 27640), (1382, 15560), (1556, 13820), (1945, 11056), (2764, 7780), (3112, 6910), (3455, 6224), (3890, 5528)]