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Is 6 a prime number?

6 is not a prime number. Here is the quickest way to see it.

The answer

No. 6 is not a prime number: 2 × 3 = 6.

How to see that 6 is not prime

6 is in the 2 times table, so 2 is a factor as well as 1 and 6.

6 has four factors: 1 and 6, plus one pair in between, 2 and 3.

Split 6 into prime factors

6 splits straight into two primes, 2 × 3, so its factor tree has only one branch.

6 in the times tables

6 turns up in 3 different times tables, the 2, 3 and 6: 2 × 3, 3 × 2 and 6 × 1.

Quick checks that catch 6

  • The last digit, 6, is even, so 2 goes in.
  • The digits add up to 6, which is in the 3 times table, so 3 goes in.
  • It is even and passes the check for 3 as well, so 6 goes in.

6 at a glance

In words
six
In Roman numerals
VI
Odd or even
Even: it ends in 6
Triangular number
1 + 2 + … + 3 = 6, a triangle of counters with 3 on the bottom row
Its factors add up to
12, or 6 without 6 itself, which makes 6 a perfect number

The numbers either side of 6

  • 5 is prime: 2 does not go into it, and 3 × 3 is already past 5. Check 5 in full
  • 7 is prime: 2 does not go into it, and 3 × 3 is already past 7. Check 7 in full

Related pages

More numbers

Questions parents ask

Which prime numbers are either side of 6?

5 below it and 7 above it, a gap of 2.

What is 6 squared?

6 × 6 = 36.

What is the smallest number with as many factors as 6?

6 itself. No smaller number has 4 factors.

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.