Is 69 a prime number?
69 is not a prime number. Here is the quickest way to see it.
The answer
No. 69 is not a prime number: 3 × 23 = 69.
How to see that 69 is not prime
Its digits add up to 6 + 9 = 15, which is a multiple of 3. That means 69 is a multiple of 3 too, so 3 is a factor.
69 has four factors: 1 and 69, plus one pair in between, 3 and 23.
Split 69 into prime factors
69 splits straight into two primes, 3 × 23, so its factor tree has only one branch.
69 in the times tables
No fact from the 2 to 12 times tables, up to × 12, makes 69. Its smallest pair, 3 × 23, needs the 23 times table, which goes past 12.
Quick checks that catch 69
- The digits add up to 15, which is in the 3 times table, so 3 goes in.
69 at a glance
- In words
- sixty-nine
- In Roman numerals
- LXIX
- Odd or even
- Odd: it ends in 9
- Its factors add up to
- 96, or 27 without 69 itself, which makes 69 a deficient number
The numbers either side of 69
- 68 is not prime. 68 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 68. Check 68 in full
- 70 is not prime. 70 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 70. Check 70 in full
Turn the digits round
69 backwards is 96. 96 is not prime. 96 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 96. Check 96 in full
Related pages
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Questions parents ask
Which prime numbers are either side of 69?
67 below it and 71 above it, a gap of 4.
What is 69 squared?
69 × 69 = 4761.
What is the smallest number with as many factors as 69?
6. It has 4 factors, the same as 69.
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.