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!
2549โ2551, 2591โ2593, 2657โ2659, 2687โ2689, 2711โ2713 ...
2617โ2621, 2659โ2663, 2683โ2687, 2689โ2693, 2707โ2711 ...
2543โ2549, 2551โ2557, 2671โ2677, 2677โ2683, 2693โ2699 ...
Primes of the form 2โฟ - 1 less than 2657
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 2657)
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