The queen of mathematics. Explore primes, congruences, and deep patterns through 83 interactive demonstrations.
See also: Rings & Fields for algebraic number rings and unique factorization domains, p-adic Numbers for the alternative completions of the rationals, and Galois Theory for solvability of Diophantine and classical problems.
Explore the building blocks of integers: divisibility, primes, and the Fundamental Theorem of Arithmetic
Master the oldest algorithm in mathematics: computing GCD through repeated division and Bézout's identity
Enter the world of clock arithmetic: congruences, modular operations, and the Chinese Remainder Theorem
Discover Fermat's Little Theorem, Euler's totient function, and the world of multiplicative functions
Explore how primes thin out among integers, the Prime Number Theorem, and the race to count primes
Explore the most important function in number theory: from Euler's product to the Riemann Hypothesis
Discover which numbers are perfect squares modulo a prime, and Gauss's "Golden Theorem"
Explore the most natural representation of real numbers and solve x² - Dy² = 1
Free exploration: factor numbers, test primality, compute with modular arithmetic, and explore sequences
Challenge yourself with questions covering all number theory concepts