Is 83 a prime number?
83 is a prime number. Here is how to check it, one division at a time.
The answer
Yes. 83 is a prime number: its only factors are 1 and 83.
How to check that 83 is prime
Try dividing 83 by the prime numbers, starting with 2. You only need primes: if 4 went into 83, then 2 would too.
- 83 ÷ 2 = 41 remainder 1, so 2 is not a factor.
- 83 ÷ 3 = 27 remainder 2, so 3 is not a factor.
- 83 ÷ 5 = 16 remainder 3, so 5 is not a factor.
- 83 ÷ 7 = 11 remainder 6, so 7 is not a factor.
Stop at 11: 11 × 11 = 121, which is more than 83. Any factor bigger than that would need a partner smaller than 11, and you have already tried those. So 83 is prime.
Where 83 comes among the primes
83 is the 23rd prime number. The prime just before it is 79.
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 83
- 83 is not in any times table from 2 to 12. The answers either side of it are 81 (9 × 9) and 84 (7 × 12 and 12 × 7).
- The nearest square number is 81 (9 × 9), 2 below it.
- Primes 4 apart are called cousin primes, and 83 has one cousin: 79.
83 at a glance
- In words
- eighty-three
- In Roman numerals
- LXXXIII
- Odd or even
- Odd: it ends in 3
- Its factors add up to
- 84, or 1 without 83 itself, which makes 83 a deficient number
Related pages
More numbers
Questions parents ask
Is 83 one of a pair of twin primes?
No. Twin primes are two primes 2 apart, such as 11 and 13. Neither 81 nor 85 is prime, so 83 has no twin.
What is the next prime number after 83?
89, which is 6 more than 83. Every number in between has a factor other than 1 and itself.
What is 83 × 83?
83 × 83 = 6889. The square of a prime has exactly three factors: 1, 83 and 6889.
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.