'''Prime
numbersnumber'''
are those is a [[natural number]]
s that
are is divisible by only 1 and itself. The only even prime number is 2. There is no upper limit to the quantity of primes, but there is no known formula for deriving the nth prime. [[Leonhard Euler]] once commented: <blockquote>
''Mathematicians have tried in vain to this day to discover some order in the sequence of prime numbers, and we have reason to believe that it is a mystery into which the mind will never penetrate.''
</blockquote>
==The Prime Numbers==
The smallest prime numbers are 2, 3, 5, 7, 11, 13... . An example of a [[composite number]] is 6, which is evenly divisible by both 2 and 3, in addition to 1 and itself.
It is easy to prove that there are an infinite number of primes using [[Euclid's second theorem]]. If there were a finite number of primes, you could multiply them all together and add 1. The resulting number would show the existence of a new prime, since it would not be divisible by any smaller prime (it would always have a remainder of 1).