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!
5519โ5521, 5639โ5641, 5651โ5653, 5657โ5659 ...
5503โ5507, 5527โ5531, 5569โ5573, 5647โ5651, 5653โ5657, 5689โ5693 ...
5521โ5527, 5557โ5563, 5563โ5569, 5641โ5647, 5683โ5689 ...
Primes of the form 2โฟ - 1 less than 5623
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 5623)
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