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!
15641โ15643, 15647โ15649, 15731โ15733, 15737โ15739 ...
15643โ15647, 15667โ15671, 15679โ15683, 15727โ15731, 15733โ15737, 15787โ15791 ...
15661โ15667, 15761โ15767, 15767โ15773, 15791โ15797, 15797โ15803, 15803โ15809 ...
Primes of the form 2โฟ - 1 less than 15731
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 15731)
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