Select any prime number greater than 3. Square it and subtract 1. What is largest number that must be a divisor of the result?

My solution:

5^2- 1.= 25 - 1 = 24 the largest number of this 24 is 24x 10^+ infinity.... that's is how i got my answer.

can anybody give any suggestion or any assistance for this problem to be answered?

thanks