Discover if your number is Prime or Composite โ fast and easy!
โ Yes! It's a Prime Number
Prime numbers are only divisible by 1 and itself.
Explore comprehensive data about prime numbers and their fascinating properties.
Click any prime to analyze it!
347โ349, 419โ421, 431โ433 ...
313โ317, 349โ353, 379โ383, 397โ401, 439โ443, 457โ461 ...
331โ337, 353โ359, 367โ373, 373โ379, 383โ389, 433โ439, 443โ449 ...
Primes of the form 2โฟ - 1 less than 389
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 389)
Prime numbers are the building blocks of mathematics, encryption, and more. Explore what makes them fascinating.
A prime number is a natural number greater than 1 that has no positive divisors other than 1
and itself.
Prime numbers cannot be formed by multiplying two smaller natural numbers. The first few are:
2, 3, 5, 7, 11, 13, 17, 19, 23...
ฯ(n) โ n/ln(n) - The density of primes decreases logarithmically
ฮถ(s) = 0 only at s = -2,-4,-6... and Re(s) = 1/2
For n > 1, there's always a prime between n and 2n
Test divisibility up to โn - Simple but slow O(โn)
Probabilistic test - Fast O(k logยณ n) with k rounds