Problem
2020 Cayley Problem 25
How many positive integers n \le 20\,000 have the properties that 2n has 64 positive divisors including 1 and 2n, and 5n has 60 positive divisors including 1 and 5n?
\textbf{(A)}\ 4\quad \textbf{(B)}\ 5\quad \textbf{(C)}\ 3\quad \textbf{(D)}\ 2\quad \textbf{(E)}\ 6
If there are no answer choices shown, enter a numerical answer.
Full credit to this problem is given to the CEMC, you may view all Cayley contests here.
Want to contribute problems and receive full credit? Click here to add your problem!
Please report any issues to us in our Discord server
Go to previous contest problem (SHIFT + Left Arrow)
Problem feedback
Difficulty
—