Math calculators
Number Theory Calculators
11 tools
GCF, LCM, factorial, permutations and combinations, Euclidean remainder, modular inverse, sequences, and prime factorization. Tools may appear in more than one topic.
Popular in Number Theory & Discrete Math
Featured tools from the Family registry.
- GCF Calculator Find the GCF, GCD, or HCF of two or more integers. Exact BigInt Euclidean fold with factor and prime cross-checks. Free, no sign-up.
- LCM Calculator Find the LCM of two or more integers with exact arithmetic and independent verification. Free, no sign-up.
- Factorial Calculator Calculate n! for integers 0 ≤ n ≤ 5000. Fast local exact integers with shareable, machine-readable results.
All Number Theory & Discrete Math
Every live calculator in this family. URLs stay /calc/math/…
- Arithmetic Sequence Calculator Nth term and partial sum of an integer arithmetic sequence. Same engine as Sequence. Not geometric. Runs locally.
- Factorial Calculator Calculate n! for integers 0 ≤ n ≤ 5000. Fast local exact integers with shareable, machine-readable results.
- Fibonacci Calculator Fibonacci numbers F_n for n ≤ 1000. F_0=0, F_1=1. Same engine as Sequence. Exact BigInt. Runs locally.
- GCF Calculator Find the GCF, GCD, or HCF of two or more integers. Exact BigInt Euclidean fold with factor and prime cross-checks. Free, no sign-up.
- Geometric Sequence Calculator Nth term and partial sum of an integer geometric sequence. Same engine as Sequence. Not arithmetic. Runs locally.
- LCM Calculator Find the LCM of two or more integers with exact arithmetic and independent verification. Free, no sign-up.
- Modular Inverse Calculator Modular inverse of a modulo m when gcd(a,m)=1. Same engine as Euclidean remainder. Not a second GCF page. Runs locally.
- Modulo Calculator Integer remainder with a = q·m + r and 0 ≤ r < |m|. Euclidean convention, not JavaScript truncated %.
- Permutation Combination Calculator Exact P(n,k) and C(n,k) for integers 0 ≤ k ≤ n ≤ 1000. Multiplicative BigInt, local-first. Not the factorial calculator.
- Prime Factorization Calculator Factor n = ∏ p^e and test primality for 1 ≤ n ≤ 10^12. Trial division. One capability, two modes.
- Sequence Calculator Integer arithmetic and geometric sequences, Fibonacci (F₀=0), and linear recurrences. Exact BigInt. Not Pascal’s triangle. Runs locally.