Is 19 Prime?

A prime number is a natural number greater than 1 that has exactly two factors: 1 and itself.

To check if 19 is prime, we need to verify that no number from 2 to √19 divides it evenly.

Since 19 is odd, we only need to check odd divisors.

We only need to test up to √19 ≈ 4.36, which rounds down to 4.

If 19 has a factor larger than √19, it must also have a corresponding factor smaller than √19.

Testing: 3, 5, 7, ... up to 4

None of these numbers divide 19 evenly.

19 has no divisors between 2 and 4.

The only factors of 19 are 1 and 19 itself.

Therefore, 19 is a PRIME number!