Number theory calculator

Number theory tools: primality testing, prime factorization, GCD/LCM, Euler's totient, divisors, Fibonacci, Collatz, and more.

Number

Number theory

Number theory studies integers and their properties. Key concepts: prime numbers (only divisible by 1 and themselves), GCD (greatest common divisor), LCM (least common multiple), Euler's totient φ(n) (count of numbers ≤ n coprime to n).

Popular prime factorization problems
Related calculators