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!
1277โ1279, 1289โ1291, 1301โ1303, 1319โ1321, 1427โ1429 ...
1279โ1283, 1297โ1301, 1303โ1307, 1423โ1427, 1429โ1433, 1447โ1451 ...
1283โ1289, 1291โ1297, 1321โ1327, 1361โ1367, 1367โ1373, 1433โ1439 ...
Primes of the form 2โฟ - 1 less than 1361
Primes that read the same forwards and backwards
Primes that remain prime when digits are rotated (below 1361)
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