Is 9 Prime?

Check if 9 is a prime number. A prime number is only divisible by 1 and itself.

Result: ✗ NO — 9 is NOT a prime number

Step-by-Step Solution

Step 1 What is a Prime Number?

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

To check if 9 is prime, we need to verify that no number from 2 to √9 divides it evenly.

Step 2 Determine Testing Range

Since 9 is odd, we only need to check odd divisors.

We only need to test up to √9 ≈ 3.00, which rounds down to 3.

If 9 has a factor larger than √9, it must also have a corresponding factor smaller than √9.

Step 3 Test Odd Divisors

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

9 ÷ 3 = 3 (no remainder!)

We found that 3 divides 9 evenly!

Step 4 Conclusion

9 = 3 × 3

Since 9 has factors other than 1 and itself, 9 is NOT a prime number.