Prime

Definition

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. In contrast, composite numbers have more than two positive divisors.

5 Must Know Facts For Your Next Test

1. The number 2 is the only even prime number.
2. Prime numbers are the building blocks of all natural numbers because any natural number can be expressed as a product of primes.
3. There are infinitely many prime numbers.
4. The Fundamental Theorem of Arithmetic states that every integer greater than 1 either is a prime itself or can be factored into primes uniquely, up to the order of factors.
5. Prime numbers can be used in various fields such as cryptography due to their unique properties.

Review Questions

• What makes a number a prime?
• Why is the number 2 unique among the primes?
• How does the Fundamental Theorem of Arithmetic relate to prime numbers?

Related terms

Composite Number: A natural number greater than 1 that has more than two positive divisors.

Fundamental Theorem of Arithmetic:

Every integer greater than 1 is either a prime or can be factored into primes uniquely, up to order.

Divisor: A number that divides another without leaving a remainder.