Is 30 a prime number?
30 is not a prime number. Here is the quickest way to see it.
The answer
No. 30 is not a prime number: 2 × 15 = 30.
How to see that 30 is not prime
30 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 30.
30 has 8 factors (1, 2, 3, 5, 6, 10, 15 and 30), which make 4 factor pairs.
Split 30 into prime factors
Split off the smallest prime each time, and keep going until every part is prime:
- 30 = 2 × 15
- 30 = 2 × 3 × 5
30 in the times tables
30 turns up in 4 different times tables, the 3, 5, 6 and 10: 3 × 10, 5 × 6, 6 × 5 and 10 × 3.
Quick checks that catch 30
- The last digit, 0, is even, so 2 goes in.
- The digits add up to 3, which is in the 3 times table, so 3 goes in.
- It ends in 0, so 5 goes in.
- It is even and passes the check for 3 as well, so 6 goes in.
- It ends in 0, so 10 goes in.
30 at a glance
- In words
- thirty
- In Roman numerals
- XXX
- Odd or even
- Even: it ends in 0
- Multiple of 10
- 3 tens
- Its factors add up to
- 72, or 42 without 30 itself, which makes 30 an abundant number
The numbers either side of 30
- 29 is prime: 2, 3 and 5 do not go into it, and 7 × 7 is already past 29. Check 29 in full
- 31 is prime: 2, 3 and 5 do not go into it, and 7 × 7 is already past 31. Check 31 in full
Related pages
More numbers
Questions parents ask
Which prime numbers are either side of 30?
29 below it and 31 above it, a gap of 2.
What is 30 squared?
30 × 30 = 900.
What is the smallest number with as many factors as 30?
24. It has 8 factors, the same as 30.
Number facts are the base of 11+ maths
Factors, multiples, primes and square numbers come up all over 11+ maths, from simplifying fractions to ratio. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.