Is 55 Prime?
Check if 55 is a prime number. A prime number is only divisible by 1 and itself.
Result:
✗ NO — 55 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 55 is prime, we need to verify that no number from 2 to √55 divides it evenly.
Step 2
Determine Testing Range
Since 55 is odd, we only need to check odd divisors.
We only need to test up to √55 ≈ 7.42, which rounds down to 7.
If 55 has a factor larger than √55, it must also have a corresponding factor smaller than √55.
Step 3
Test Odd Divisors
Testing: 3, 5, 7, ... up to 7
55 ÷ 3 = 18 remainder 1
55 ÷ 5 = 11 (no remainder!)
We found that 5 divides 55 evenly!
Step 4
Conclusion
55 = 5 × 11
Since 55 has factors other than 1 and itself, 55 is NOT a prime number.