Is 46 a prime number?
46 is not a prime number. Here is the quickest way to see it.
The answer
No. 46 is not a prime number: 2 × 23 = 46.
How to see that 46 is not prime
46 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 46.
46 has four factors: 1 and 46, plus one pair in between, 2 and 23.
Split 46 into prime factors
46 splits straight into two primes, 2 × 23, so its factor tree has only one branch.
46 in the times tables
No fact from the 2 to 12 times tables, up to × 12, makes 46. Its smallest pair, 2 × 23, needs the 23 times table, which goes past 12.
Quick checks that catch 46
- The last digit, 6, is even, so 2 goes in.
46 at a glance
- In words
- forty-six
- In Roman numerals
- XLVI
- Odd or even
- Even: it ends in 6
- Its factors add up to
- 72, or 26 without 46 itself, which makes 46 a deficient number
The numbers either side of 46
- 45 is not prime. Its digits add up to 4 + 5 = 9, which is a multiple of 3. That means 45 is a multiple of 3 too, so 3 is a factor. Check 45 in full
- 47 is prime: 2, 3 and 5 do not go into it, and 7 × 7 is already past 47. Check 47 in full
Turn the digits round
46 backwards is 64. 64 is not prime. 64 is even, and every even number can be divided by 2, so 2 is a factor as well as 1 and 64. Check 64 in full
Related pages
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Questions parents ask
Which prime numbers are either side of 46?
43 below it and 47 above it, a gap of 4.
What is 46 squared?
46 × 46 = 2116.
What is the smallest number with as many factors as 46?
6. It has 4 factors, the same as 46.
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.