What is a Prime Number?
A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. In simpler terms, it is a number that has exactly two distinct positive divisors: 1 and itself.
Examples
- 2, 3, 5, 7, 11, 13, 17, 19... are prime numbers.
- 4 is not prime: It can be divided by 1, 2, and 4.
- 1 is not prime: By definition, a prime must have exactly two divisors. 1 has only one (itself).
Why are Primes Important?
Prime numbers are the "atoms" of mathematics. They are fundamental in number theory and are essential for modern cryptography and encryption (like RSA algorithms), which keep our internet data secure.