Is 48 a prime number?
48 is not a prime number. Here is a way to check it.
The answer
No. 48 is not a prime number: 2 × 24 = 48.
How to see that 48 is not prime
48 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 48.
48 has 10 factors (1, 2, 3, 4, 6, 8, 12, 16, 24 and 48), which make 5 factor pairs.
Split 48 into prime factors
Split off the smallest prime each time, and keep going until every part is prime:
- 48 = 2 × 24
- 48 = 2 × 2 × 12
- 48 = 2 × 2 × 2 × 6
- 48 = 2 × 2 × 2 × 2 × 3
With repeated primes written as powers, that is 2⁴ × 3. A small raised number tells you how many times to use that factor: for example, 2³ means 2 × 2 × 2.
48 in the times tables
48 turns up in 4 different times tables, the 4, 6, 8 and 12: 4 × 12, 6 × 8, 8 × 6 and 12 × 4.
Quick checks that catch 48
- The last digit, 8, is even, so 2 goes in.
- The digits add up to 12, which is in the 3 times table, so 3 goes in.
- Half of it is 24, which is still even, so 4 goes in.
- It is even and passes the check for 3 as well, so 6 goes in.
48 at a glance
Optional extra number facts:
- In words
- forty-eight
- In Roman numerals
- XLVIII
- Odd or even
- Even: it ends in 8
- Its factors add up to
- 124, or 76 without 48 itself. 48 is abundant: Abundant means this sum is greater than the number.
The numbers either side of 48
- 47 is prime: 2, 3 and 5 do not go into it, and 7 × 7 is already past 47. Check 47 in full
- 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
Turn the digits round
48 backwards is 84. 84 is not prime. 84 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 84. Check 84 in full
Related pages
More numbers
Questions parents ask
Which prime numbers are either side of 48?
47 below it and 53 above it, a gap of 6.
What is 48 squared?
48 × 48 = 2304.
What is the smallest number with as many factors as 48?
48 itself. No smaller number has 10 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.