Prime Number Checker
Are you asking:Â is this number prime? Use this Prime Number Checker to find out whether a number is prime or not. The tool will also show factors for each number.
Prime Number Checker
​How to Use the Prime Number Checker
- When you first visit the page, you'll see a box labeled "Enter a Number." Click on this box to type in the number you want to check.
- Enter a positive integer that you wish to check if it's a prime number. For example, if you want to check if 7 is a prime number, you would type "7" (without the quotation marks) into the box.
Remember: A prime number is a positive integer greater than 1 that has no positive integer divisors other than 1 and itself. For example, the first six prime numbers are 2, 3, 5, 7, 11, and 13. - Once you've typed in your number, click on the "Check" button located below the input box. The result will be displayed below the button.
- The output will include two pieces of information:
- A statement whether your number is a prime number or not.
- A list of factors for your number. Factors are numbers that divide evenly into another number.
- If you entered a non-integer or a negative number, you will see an error message asking you to enter a valid positive integer number. Simply erase your previous entry in the input box and enter a valid number to proceed.
- To check another number, just erase your previous input and repeat the process. You can use this tool as many times as you want, to check as many numbers as you wish.
​What are Prime Numbers?
In the simplest terms, a prime number is a number that has only two different factors: 1 and the number itself. This means that a prime number can be divided evenly only by 1 and by itself.
Take the number 7, for example. The only numbers that can divide 7 without leaving any remainder are 1 and 7. So, 7 is a prime number.
Spotting Prime Numbers
To identify prime numbers, start with small numbers and work your way up. The number 2 is the smallest prime number and it's also the only even prime number because all other even numbers can be divided by 2.
Here are the first few prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29. Notice something interesting? None of them can be divided evenly by any other number but 1 and the number itself.
Numbers That Are Not Prime
Any number that can be divided evenly by more numbers than 1 and itself is not a prime number. These numbers are called composite numbers.
For example, the number 4 can be divided evenly by 1, 2, and 4. That's more than just 1 and 4, so 4 is not a prime number. The number 6 is another example, which can be divided evenly by 1, 2, 3, and 6. So, 6 is not a prime number.
Sometimes you might come across a number that can only be divided evenly by 1 and itself, but it's still not a prime number. The perfect example is 1. While it's true that 1 can only be divided evenly by 1, it's not considered a prime number. By definition, a prime number has two distinct factors, and for 1, there's only one factor - 1.
The Role of Prime Numbers in Mathematics
In the grand scheme of mathematics, prime numbers play a vital role. According to the Fundamental Theorem of Arithmetic, every whole number greater than 1 is either a prime number itself or can be broken down, or factored, into a unique set of prime numbers.
For example, let's take the number 12. It's not a prime number because it can be divided evenly by 1, 2, 3, 4, 6, and 12. But we can break down 12 into prime numbers. Here's how:
Understanding prime numbers is a stepping stone into the deeper concepts of mathematics. With a clear definition and examples in mind, you're well-equipped to identify and work with prime numbers. Remember, practice makes perfect. So, try finding prime numbers and their factors, and soon it'll become second nature to you.
Take the number 7, for example. The only numbers that can divide 7 without leaving any remainder are 1 and 7. So, 7 is a prime number.
Spotting Prime Numbers
To identify prime numbers, start with small numbers and work your way up. The number 2 is the smallest prime number and it's also the only even prime number because all other even numbers can be divided by 2.
Here are the first few prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29. Notice something interesting? None of them can be divided evenly by any other number but 1 and the number itself.
Numbers That Are Not Prime
Any number that can be divided evenly by more numbers than 1 and itself is not a prime number. These numbers are called composite numbers.
For example, the number 4 can be divided evenly by 1, 2, and 4. That's more than just 1 and 4, so 4 is not a prime number. The number 6 is another example, which can be divided evenly by 1, 2, 3, and 6. So, 6 is not a prime number.
Sometimes you might come across a number that can only be divided evenly by 1 and itself, but it's still not a prime number. The perfect example is 1. While it's true that 1 can only be divided evenly by 1, it's not considered a prime number. By definition, a prime number has two distinct factors, and for 1, there's only one factor - 1.
The Role of Prime Numbers in Mathematics
In the grand scheme of mathematics, prime numbers play a vital role. According to the Fundamental Theorem of Arithmetic, every whole number greater than 1 is either a prime number itself or can be broken down, or factored, into a unique set of prime numbers.
For example, let's take the number 12. It's not a prime number because it can be divided evenly by 1, 2, 3, 4, 6, and 12. But we can break down 12 into prime numbers. Here's how:
- Start by dividing 12 by the smallest prime number, 2. That gives you 6.
- You can divide 6 by 2 again, and you get 3.
- Now, 3 is a prime number itself.
Understanding prime numbers is a stepping stone into the deeper concepts of mathematics. With a clear definition and examples in mind, you're well-equipped to identify and work with prime numbers. Remember, practice makes perfect. So, try finding prime numbers and their factors, and soon it'll become second nature to you.