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!
19991โ19993, 20021โ20023, 20147โ20149 ...
19993โ19997, 20047โ20051, 20113โ20117, 20143โ20147, 20173โ20177 ...
20023โ20029, 20101โ20107, 20107โ20113, 20117โ20123, 20123โ20129 ...
Primes of the form 2โฟ - 1 less than 20089
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 20089)
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