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!
17909โ17911, 17921โ17923, 17957โ17959, 17987โ17989, 18041โ18043, 18047โ18049, 18059โ18061 ...
17977โ17981, 18043โ18047 ...
17903โ17909, 17923โ17929, 17971โ17977, 17981โ17987 ...
Primes of the form 2โฟ - 1 less than 17971
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 17971)
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