Is 97 a prime number?
97 is a prime number. Here is how to check it, one division at a time.
The answer
Yes. 97 is a prime number: its only factors are 1 and 97.
How to check that 97 is prime
Try dividing 97 by the prime numbers, starting with 2. You only need primes: if 4 went into 97, then 2 would too.
- 97 ÷ 2 = 48 remainder 1, so 2 is not a factor.
- 97 ÷ 3 = 32 remainder 1, so 3 is not a factor.
- 97 ÷ 5 = 19 remainder 2, so 5 is not a factor.
- 97 ÷ 7 = 13 remainder 6, so 7 is not a factor.
Stop at 11: 11 × 11 = 121, which is more than 97. Any factor bigger than that would need a partner smaller than 11, and you have already tried those. So 97 is prime.
Where 97 comes among the primes
97 is the 25th prime number. The prime just before it is 89.
There are 25 prime numbers up to 100: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89 and 97.
Around 97
- 97 is not in any times table from 2 to 12. The answers either side of it are 96 (8 × 12 and 12 × 8) and 99 (9 × 11 and 11 × 9).
- The nearest square number is 100 (10 × 10), 3 above it.
- Primes 4 apart are called cousin primes, and 97 has one cousin: 101.
97 at a glance
- In words
- ninety-seven
- In Roman numerals
- XCVII
- Odd or even
- Odd: it ends in 7
- Its factors add up to
- 98, or 1 without 97 itself, which makes 97 a deficient number
Related pages
More numbers
Questions parents ask
Is 97 one of a pair of twin primes?
No. Twin primes are two primes 2 apart, such as 11 and 13. Neither 95 nor 99 is prime, so 97 has no twin.
What is the next prime number after 97?
101, which is 4 more than 97. Every number in between has a factor other than 1 and itself.
What is 97 × 97?
97 × 97 = 9409. The square of a prime has exactly three factors: 1, 97 and 9409.
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.