Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
A prime number is a positive integer greater than 1 that has no positive divisors other than 1 and itself. In simpler terms, it's a number that cannot be evenly divided by any other numbers except for 1 and itself.
Related terms
Composite number: A composite number is an integer greater than 1 that can be evenly divided by numbers other than 1 and itself. In contrast to prime numbers, composite numbers have multiple factors.
Sieve of Eratosthenes: The Sieve of Eratosthenes is an algorithm used to find all prime numbers up to a given limit. It works by iteratively marking the multiples of each prime number, gradually eliminating non-prime numbers from a list.
Prime factorization: Prime factorization is the process of expressing a composite number as a product of its prime factors. It involves finding the prime numbers that can divide the given number without leaving any remainder.