The number of ways in which 1800 can be divided into two factors is 

$1800=2^3\times 3^2\times 5^2$

Total no of divisors = (3+1) (2+1) (2+1)

                                   = 4(3) (3)=36

No of ways in which 1800 is divided into 2 factors $=\frac{36}{2}=18$