What Is a Prime Number?
A prime number is a whole number greater than 1 whose only positive divisors are 1 and itself, such as 2, 3, 5, 7, 11, and 13. A whole number greater than 1 that is not prime is called composite. The number 1 is neither prime nor composite, and 2 is the only even prime.
Why Primes Matter
Every whole number greater than 1 can be written as a product of primes in exactly one way (apart from order), which is the basis of prime factorization.
🧮 Calculate It Yourself
Put Prime Number into practice with this free calculator — no sign-up, nothing stored.
🔗 Related Terms
More Math & Statistics Terms
📖 Browse all glossary terms or explore all free calculators.
Last updated: September 27, 2026. This definition is for general educational purposes only. It is not financial, investment, tax, legal, or medical advice, and it does not recommend any product or course of action. For decisions about your own situation, consult a qualified professional.