In the following alphametic equation each capital letter in bold represents a different base x digit from 0 to x-1. None of the numbers can contain any leading zero.

PRIME + PRIME + PRIME = NUMBER

Determine the minimum positive integer value of x such that PRIME is a prime number.

Bonus Question:

What would have been the minimum positive integer value of x, if each capital letter in bold represented a different base x prime digit from 2 to x-1?