# What Is A Prime Number

## Prime Number Definition

**Prime number is a positive, round number, bigger than 1, that has only 2 positive divisors 1 and the number itself!**

That’s it! This is what a prime number is, explained in very simple words. This definition might be enough for you to understand the matter, but we suggest that you take a look at the following lines:

So here we will answer the question – “What is a prime number?” going through some more details. It should be very clear, that for a number to be prime, it has too meet all of the following requirements:

1. It should be positive

2. It should be round

3. Bigger than 1

4. The number has to have only 2 positive divisors – 1 (one) and itself

If ANY of these simple conditions are not met for a specific number, we can be very sure, that it is not a prime. Now to get extremely clear for you, have a look at the following examples:

* The number 8 is not prime, because it has more than 2 positive divisors (factors): 2,4,8,1

* 7 is a prime number, because it meets all of the conditions above and has only 2 positive divisors – 1 and 7.

* 991 is a prime number, because it meets all of the criteria

* 992 is NOT prime, because it has more than 2 divisors

The number ” 2 ” is the only even prime. As you know, every even number can be divided into 2, so this is the third sure divisor for any of them, except 1 and themselves. Condition 4 is not met.

### Is 1 a Prime Number?

According to our definition, the number ” 1 ” doesn’t meet the third criteria – to be bigger than 1. Additionally, it doesn’t have two divisors, it has only one – itself. So we can say, that *one is not a prime*.

Every number that is not prime is called a composite number. Prime numbers are infinite. Primes were explored for the first time by Euclid, nearly 300 years B.C.

### Prime Number Checker

If you are experiencing any difficulties with determining the primeness of a number, using the simple conditions from above, you can simply use this online prime checker. Just enter a number and click on the button, to check it.

Enter a number to see if it’s prime or not:

Enter the number: | Prime factors are: | H |

### Prime Numbers List Generator

You can use this nice widget – primes list generator, with which you can generate your custom list of prime numbers. Follow the link to sees and use the tool and to get some more details about it…

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show me the math