[tokenadult]

Heck, there are infinite prime numbers, all of which are natural numbers.

http://primes.utm.edu/notes/proofs/infinite/euclids.html

http://mathworld.wolfram.com/EuclidsTheorems.html

http://www-users.cs.york.ac.uk/susan/cyc/p/primeprf.htm

http://primes.utm.edu/notes/proofs/infinite/