Welcome to the Math Salamanders What is a Prime Number? page.

Hopefully all (or nearly all) your questions about prime numbers will be answered here!

There are also links to our prime number charts page and our prime number calculator.

How to Print or Save these sheets

- Follow the 3 easy steps below to get your worksheets printed out perfectly!

Step 1

Click it.

Step 2

Magnify it

(if needed).

Step 3

Print it!

Need further help? Use our How to Print Support Page

How to Print or Save these sheets

Need help with printing or saving?

Follow these 3 easy steps to get your worksheets printed out perfectly!

- A prime number is a number that is only divisible by itself and 1.
- It must also be greater than one.

Another way of saying this is that the only factors of a prime number are 1 and the number itself.

11 is prime because its only factors are 1 and 11.

17 is prime because its only factors are 1 and 17.

53 is prime because its only factors are 1 and 53.

15 is NOT prime because it has 4 factors: 1, 3, 5 and 15.

28 is NOT prime because it has 6 factors: 1, 2, 4, 7, 14 and 28.

On our Prime Number Charts page, we have many printable lists of prime numbers.

You can find the first 100 prime numbers, or print out a list of all prime numbers below 10,000.

We also have a prime number calculator which will find all the primes in a range that you set, and also a prime number tester which gives all the factors of a number, and tells you whether it is prime or not.

The simple answer to this question is no.

Prime numbers have many different and interesting properties, which they would not have if the number one was prime.

Therefore, the number 1 was excluded from the set of prime numbers.

So the first prime number is 2.

The answer to this question is no.

All prime numbers belong to the set of natural numbers or positive integers.

The answer to this question is again no.

All prime numbers belong to the set of natural numbers or positive integers.

They cannot be decimals or fractions.

The answer to this question is yes.

However, there is only one even prime number which is 2.

No other even numbers can be prime as they will have 2 as a factor (as well as themselves and one).

The first ten prime numbers are...

All the prime numbers between 1 and 100 are...

There are 25 prime numbers between 1 and 100.

What is the ...th prime number? |
Number |

1st | 2 |

10th | 29 |

50th | 229 |

100th | 541 |

500th | 3571 |

1,000th | 7,919 |

10,000th | 104,729 |

How many prime numbers between... |
Number of Primes |
Percentage |

1 and 100 |
25 |
25% |

1 and 1000 |
168 |
16.8% |

1 and 10000 |
1229 |
12.3% |

1 and 100,000 |
9592 |
9.6% |

1 and 1,000,000 |
78498 |
7.8% |

What this shows is that as the range of numbers gets large, the density of prime numbers gets smaller.

So the prime numbers become more spread out as the numbers get larger.

So the next question I'm betting you want to know is: "If the prime numbers become more spread out as the numbers get larger and larger, do they eventually stop?"

Well, the answer is no.

The set of prime numbers is infinite and there are several different proofs to demonstrate this!

One such proof is given here on the primes.utm.edu website.

The Sieve of Erastosthenes is a method for finding what is a prime numbers between 2 and any given number.

Eratosthenes was a Greek mathematician (as well as being a poet, an astronomer and musician) who lived from about 276BC to 194BC.

If you want to find out more about his sieve for finding primes, and print out some Sieve of Eratosthenes worksheets, use the link below.

If you have any more questions about what is a prime number, or questions about primes, please feel free to leave us a comment below.

Alternatively, you can use the contact us form at the top and bottom of each page.

Return to Free Math Help Online Hub

Return from What is Prime Number page to Math Salamanders Homepage

Math-Salamanders.com

The Math Salamanders hope you enjoy using these free printable Math worksheets and all our other Math games and resources.

We welcome any comments about our site or worksheets on the Facebook comments box at the bottom of every page.

Search here!

Looking for some fun printable math games?

We have some great games for you to play in our Math Games e-books!

- Online Times Table Practice
- Online + and - Practice
- Times Table Worksheets
- Geometry Sheets
- Fraction Sheets
- Money Sheets
- Math Games
- Fun Math Puzzles & Activities
- Math Help Pages

Have a look at some of our most popular pages to see different Math activities and ideas you could use with your child

- List of Geometric Shapes
- Equivalent Fractions
- Printable Shapes
- 3d Geometric Shapes
- Perimeter Worksheets

Looking for a new direction in your life in 2018?

Got a hobby or passion you want to share?

Create your own business from the comfort of your home...

Expand your horizons with SBI!

I used this to develop my site in 2010, and have never looked back!

Click here for my story!

If you are a regular user of our site and appreciate what we do, please consider making a small donation to help us with our costs.

Get a free sample copy of our Math Salamanders Dice Games book with each donation!

Looking for some cool math certificates to hand out?

A certificate is a great way to praise achievement in math learning.

Check out our printable math certificate collection!

## New! Comments

Have your say about the Math resources on this page! Leave me a comment in the box below.