Problem Link : http://codeforces.com/problemset/problem/230/B
This problem asks you to find positive integers that can be divided by three different positive integers.
Ideal candidates for T-Prime numbers would be numbers that is formed by power of two of an integer. This means that the number supplied by the problem must have integer square root.
However, that is not enough to ensure that it would be a T-Prime number. If the roots are not prime, the number supplied can be divided by more than 3 positive integers.
Hence the root should be prime.