21209420

素因数分解:

$2^2\times 5^1\times {\mathrm{73}}^2\times {\mathrm{199}}^1$

素因数の和:354

約数の個数: 36

約数和(自身を含む): 45385200

約数和(自身を除く): 24175780

約数列:

[1, 2, 4, 5, 10, 20, 73, 146, 199, 292, 365, 398, 730, 796, 995, 1460, 1990, 3980, 5329, 10658, 14527, 21316, 26645, 29054, 53290, 58108, 72635, 106580, 145270, 290540, 1060471, 2120942, 4241884, 5302355, 10604710, 21209420]

約数ペア:

[(1, 21209420), (2, 10604710), (4, 5302355), (5, 4241884), (10, 2120942), (20, 1060471), (73, 290540), (146, 145270), (199, 106580), (292, 72635), (365, 58108), (398, 53290), (730, 29054), (796, 26645), (995, 21316), (1460, 14527), (1990, 10658), (3980, 5329)]