Composite Number Calculator
Test if a number is composite, view its factor count, and classify numbers as prime, composite, or neither.
What is a Composite Number?
A composite number is a positive integer greater than 1 that has at least one positive factor other than 1 and itself. The number 12 is composite because 12 has 6 factors: 1, 2, 3, 4, 6, and 12. Every composite number can be expressed as a product of prime numbers through prime factorization.
Between 1 and 100, there are 74 composite numbers and 25 prime numbers. The number 1 is classified as neither prime nor composite. Every even number greater than 2 is composite (divisible by 2). The smallest composite number is 4 = 2 × 2.
Composite vs Prime Numbers
Every integer from 1 to 50 classified: prime (blue), composite (violet), or neither (gray).
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Prime Composite Neither (1)
Frequently Asked Questions
No, 0 is neither prime nor composite. Composite numbers must be positive integers greater than 1 with more than 2 factors. The number 0 is divisible by every non-zero integer, giving it infinitely many factors — which places 0 outside both the prime and composite categories.