article

Prime Number Checker

Email
Submitted on: 5/5/2018 5:48:19 PM
By: Gaurav Singh  
Level: Beginner
User Rating: Unrated
Compatibility: PHP 5.0
Views: 874
 
     How to Check if a Number is Prime

 
				A prime number (or a prime) is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself. However, 6 is composite because it is the product of two numbers (2 × 3) that are both smaller than 6. Primes are central in number theory because of the fundamental theorem of arithmetic: every natural number greater than 1 is either a prime itself or can be factorized as a product of primes that is unique up to their order.
The property of being prime is called primality. A simple but slow method of checking the primality of a given number n {\displaystyle n} n, called trial division, tests whether n {\displaystyle n} n is a multiple of any integer between 2 and n {\displaystyle {\sqrt {n}}} {\sqrt {n}}. Faster algorithms include the Miller–Rabin primality test, which is fast but has a small chance of error, and the AKS primality test, which always produces the correct answer in polynomial time but is too slow to be practical. Particularly fast methods are available for numbers of special forms, such as Mersenne numbers. As of January 2018, the largest known prime number has 23,249,425 decimal digits.
Check if Prime Number Calculator 
Note : This Prime Number Calculator performs primality test and checks if a positive number is prime. 


Other 1 submission(s) by this author

 


Report Bad Submission
Use this form to tell us if this entry should be deleted (i.e contains no code, is a virus, etc.).
This submission should be removed because:

Your Vote

What do you think of this article (in the Beginner category)?
(The article with your highest vote will win this month's coding contest!)
Excellent  Good  Average  Below Average  Poor (See voting log ...)
 

Other User Comments


 There are no comments on this submission.
 

Add Your Feedback
Your feedback will be posted below and an email sent to the author. Please remember that the author was kind enough to share this with you, so any criticisms must be stated politely, or they will be deleted. (For feedback not related to this particular article, please click here instead.)
 

To post feedback, first please login.