Is 50 a prime number?
50 is not a prime number. Here is a way to check it.
The answer
No. 50 is not a prime number: 2 × 25 = 50.
How to see that 50 is not prime
50 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 50.
50 has 6 factors (1, 2, 5, 10, 25 and 50), which make 3 factor pairs.
Split 50 into prime factors
Split off the smallest prime each time, and keep going until every part is prime:
- 50 = 2 × 25
- 50 = 2 × 5 × 5
With repeated primes written as powers, that is 2 × 5². A small raised number tells you how many times to use that factor: for example, 2³ means 2 × 2 × 2.
50 in the times tables
50 turns up in 2 different times tables, the 5 and 10: 5 × 10 and 10 × 5.
Quick checks that catch 50
- The last digit, 0, is even, so 2 goes in.
- It ends in 0, so 5 goes in.
- It ends in 0, so 10 goes in.
50 at a glance
Optional extra number facts:
- In words
- fifty
- In Roman numerals
- L
- Odd or even
- Even: it ends in 0
- Multiple of 10
- 5 tens
- Its factors add up to
- 93, or 43 without 50 itself. 50 is deficient: Deficient means this sum is less than the number.
The numbers either side of 50
- 49 is not prime. 49 is odd, its digits do not add up to a multiple of 3, and it does not end in 5, so the quick checks for 2, 3 and 5 all fail. Try 7 next: 7 × 7 = 49. Check 49 in full
- 51 is not prime. Its digits add up to 5 + 1 = 6, which is a multiple of 3. That means 51 is a multiple of 3 too, so 3 is a factor. Check 51 in full
Related pages
More numbers
Questions parents ask
Which prime numbers are either side of 50?
47 below it and 53 above it, a gap of 6.
What is 50 squared?
50 × 50 = 2500.
What is the smallest number with as many factors as 50?
12. It has 6 factors, the same as 50.
Continue your number practice
Explore the diagnostic for another set of practice questions.