Is 131 Prime?

Check if 131 is a prime number. A prime number is only divisible by 1 and itself.

Is prime?
Result: ✓ YES — 131 is 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 131 is prime, we need to verify that no number from 2 to √131 divides it evenly.

Step 2 Determine Testing Range

Since 131 is odd, we only need to check odd divisors.


We only need to test up to √131 ≈ 11.45, which rounds down to 11.


If 131 has a factor larger than √131, it must also have a corresponding factor smaller than √131.

Step 3 Test Odd Divisors

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


131 ÷ 3 = 43 remainder 2
131 ÷ 5 = 26 remainder 1
131 ÷ 7 = 18 remainder 5
131 ÷ 9 = 14 remainder 5
131 ÷ 11 = 11 remainder 10

None of these numbers divide 131 evenly.

Step 4 Conclusion

131 has no divisors between 2 and 11.


The only factors of 131 are 1 and 131 itself.


Therefore, 131 is a PRIME number!