Factor Finder
The motivation for this comes from The Big Book of Small Python Projects. This is #24, Factor Finder.
Factors are a common mathematical concept. A number x is a factor of another number, y, if and only if x can evenly divide y. A number that has no factors other than 1 and itself is a prime number. Prime numbers play a role in fields like cryptography and number theory.
If you find a prime number as you search for factors, you're in for a treat!