Mainly, because it can help with stuff like mental processing from developers, better management, and sometimes easier life for accountants. 137 as an odd and e

Mainly, because it can help with stuff like mental processing from developers, better management, and sometimes easier life for accountants. 137 as an odd and even prime number is hard to divide. Lots more, if you can use certain subset of all numbers, you don't have to remember that many different cases.