math

Prime Number

A natural number greater than 1 that has no positive divisors other than 1 and itself.

A prime number can only be divided evenly by 1 and itself. The first 10 primes: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29.

2 is the only even prime number
There are infinitely many primes (proved by Euclid ~300 BC)
Every integer > 1 can be uniquely factored into primes (Fundamental Theorem of Arithmetic)

To check if n is prime, test divisibility by all primes up to √n. If none divide evenly, n is prime.

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