Numbers
15Number Base Converter
Convert numbers between any bases 2–36.
Roman Numerals
Convert between Roman numerals and integers.
Prime Number Checker
Check if a number is prime and list factors.
Prime Factorization
Decompose a number into prime factors.
GCD & LCM
Compute GCD and LCM of two numbers.
Fibonacci Sequence
Generate Fibonacci numbers up to N.
Modular Arithmetic
Operations under a given modulus.
Extended Euclidean
Find Bézout coefficients with extended GCD.
Chinese Remainder Theorem
Solve systems of congruences.
Euler's Totient φ(n)
Compute Euler's totient function.
Number to Words
Spell out a number in English words.
Big Number Arithmetic
Add, subtract, multiply large integers.
Continued Fractions
Convert fractions to/from continued fractions.
Collatz Sequence
Generate the Collatz (3n+1) sequence.
Number Bases Table
Show a number in all common bases simultaneously.