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!
1931โ1933, 1949โ1951, 1997โ1999, 2027โ2029 ...
1993โ1997, 1999โ2003 ...
1901โ1907, 1907โ1913, 1973โ1979, 1987โ1993, 2011โ2017, 2063โ2069 ...
Primes of the form 2โฟ - 1 less than 1993
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 1993)
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