X : an integer ,So 1/X terminates, X has to do what.?

Question

Does X has to terminate,non-terminate,repeat,non-repeat or what?

Then is 1/X a rational or irrational number.

Answer 1

X cannot have any prime factors other than 2 or 5. Thats because 2 and 5 are the only prime factors of 10, which is the base you are working in (and if you changed base, the same idea still works.)

Replying to your extra questions: well, X is an integer, of course it terminates. As for 1/X, its a rational of course, but that has nothing to do with it terminating or not.