Is 125 Prime?

Check if 125 is a prime number. A prime number is only divisible by 1 and itself.

Result: ✗ NO — 125 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 125 is prime, we need to verify that no number from 2 to √125 divides it evenly.

Step 2 Determine Testing Range

Since 125 is odd, we only need to check odd divisors.

We only need to test up to √125 ≈ 11.18, which rounds down to 11.

If 125 has a factor larger than √125, it must also have a corresponding factor smaller than √125.

Step 3 Test Odd Divisors

Testing: 3, 5, 7, ... up to 11

125 ÷ 3 = 41 remainder 2

125 ÷ 5 = 25 (no remainder!)

We found that 5 divides 125 evenly!

Step 4 Conclusion

125 = 5 × 25

Since 125 has factors other than 1 and itself, 125 is NOT a prime number.