The maximum value of the natural number $n$ for which $21^n$ divides $50!$ is

If one of the factors of the number $3^{7} 2^{8} 17^{3}$ is randomly chosen, then the probability that the chosen factor will be a perfect square is

The number of positive integers that divide $(1890) \cdot (130) \cdot (170)$ and are not divisible by $45$ is ________

The number of factors of 1800 that are multiple of 6 is:

The number of factors of $3^5 \times 5^8 \times 7^2$ that are perfect squares is