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Is 2 a prime number?

2 is a prime number, and the only even one.

The answer

Yes. 2 is a prime number: its only factors are 1 and 2. It is the only even prime number.

Why 2 is prime

There is no whole number between 1 and 2, so nothing else can go into 2 exactly. Its only factors are 1 and 2.

2 is the only even prime. Every other even number can be divided by 2, so it has at least three factors: 1, 2 and itself.

Where 2 comes among the primes

2 is the 1st prime number, the very first one.

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 2

  • 2 is in only one times table, its own, as 2 × 1. The next answer in it is 2 × 2 = 4.
  • The nearest square number is 1 (1 × 1), 1 below it.

2 at a glance

In words
two
In Roman numerals
II
Odd or even
Even: it ends in 2
Its factors add up to
3, or 1 without 2 itself, which makes 2 a deficient number

Related pages

More numbers

Questions parents ask

Is 2 one of a pair of twin primes?

No. Twin primes are two primes 2 apart, such as 3 and 5. 0 and 4 are not prime, so 2 has no twin.

What is 2 × 2?

2 × 2 = 4. The square of a prime has exactly three factors: 1, 2 and 4.

What is the next prime number after 2?

3. 2 and 3 are the only two primes next to each other, because every other pair of neighbours includes an even number bigger than 2.

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.