5. (6 points) Given $300=2 \times 2 \times 3 \times 5 \times 5$, then 300 has $\qquad$ different divisors.
【Solution】Solution: $300=2^{2} \times 3 \times 5^{2}$,
Therefore, the number of divisors of 300 is: $(2+1) \times(1+1) \times(2+1)=3 \times 2 \times 3=18$ (divisors), Answer: 300 has a total of 18 different divisors. Hence the answer is: 18.