Is 58 a prime number?
58 is not a prime number. Here is the quickest way to see it.
The answer
No. 58 is not a prime number: 2 × 29 = 58.
How to see that 58 is not prime
58 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 58.
58 has four factors: 1 and 58, plus one pair in between, 2 and 29.
Split 58 into prime factors
58 splits straight into two primes, 2 × 29, so its factor tree has only one branch.
58 in the times tables
No fact from the 2 to 12 times tables, up to × 12, makes 58. Its smallest pair, 2 × 29, needs the 29 times table, which goes past 12.
Quick checks that catch 58
- The last digit, 8, is even, so 2 goes in.
58 at a glance
- In words
- fifty-eight
- In Roman numerals
- LVIII
- Odd or even
- Even: it ends in 8
- Its factors add up to
- 90, or 32 without 58 itself, which makes 58 a deficient number
The numbers either side of 58
- 57 is not prime. Its digits add up to 5 + 7 = 12, which is a multiple of 3. That means 57 is a multiple of 3 too, so 3 is a factor. Check 57 in full
- 59 is prime: 2, 3, 5 and 7 do not go into it, and 11 × 11 is already past 59. Check 59 in full
Turn the digits round
58 backwards is 85. 85 is not prime. 85 ends in 5, and every number ending in 5 or 0 is in the 5 times table, so 5 is a factor. Check 85 in full
Related pages
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Questions parents ask
Which prime numbers are either side of 58?
53 below it and 59 above it, a gap of 6.
What is 58 squared?
58 × 58 = 3364.
What is the smallest number with as many factors as 58?
6. It has 4 factors, the same as 58.
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.