If these are really, truly ID numbers (randomly assigned and having to other purpose in life that to be used as keys into the Data Base), then they should be defined as a character-string, not as numeric data.

Think about it, when was the last time you added together your Master-Card number and your Visa number? The fact that a piece of data consists entirely of numbers does not automatically mean that it is a meaningful number subject to the whims of Arithmetic and Algebra.