What is a prime number?

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. In other words, it can only be divided evenly by 1 and the number itself. For example, 7 is prime because it can only be divided by 1 and 7, while 6 is not prime because it can be divided by 1, 2, 3, and 6. Prime numbers are fundamental building blocks in mathematics and play a crucial role in number theory, cryptography, and computer science.

Tool description

This Prime Number Checker instantly determines whether any number is prime or composite. Simply enter a number and get immediate results showing if it's prime, along with all its divisors if it's composite. The tool uses an efficient algorithm to check primality and find all factors, making it perfect for students learning number theory, developers working with cryptography, or anyone curious about the properties of numbers.

Features

  • Instant primality testing - Checks if a number is prime in milliseconds
  • Divisor listing - Shows all divisors (excluding 1 and the number itself) for composite numbers
  • Large number support - Handles numbers up to JavaScript's maximum safe integer
  • Clear results - Displays whether a number is prime, composite, or neither (0 and 1)
  • Educational feedback - Provides detailed information about the number's properties

Use cases

  • Math education - Students learning about prime numbers and factors
  • Cryptography - Developers testing prime numbers for encryption algorithms
  • Number theory research - Mathematicians exploring prime number patterns
  • Programming practice - Verifying primality algorithms and implementations
  • Competitive programming - Quick testing of prime-related problems