Prime numbers are those which can be divided by one and themselves. These are important for computer encryption. As a part of the Great Internet Mersenne Prime Search (Gimps) program which was founded in 1996, the largest known prime number has been discovered. So far 15 such record prime numbers have been discovered under it.

This prime number is written as 2^74,207,281-1 or M74207281. It has over 22 million digits in it; 22,338,618 to be accurate! It is calculated by multiplying 74,207,281 twos together, and then subtracting one from it.

The record-beating discovery was made using a computer program by Dr Curtis Cooper at the University of Central Missouri. Dr Cooper also is the proud discoverer of the previous largest prime number which he found in 2013.  The new prime number is five million digits longer than its antecedent.  

Prime numbers are used as encryption keys by shopping private message services and online banking, to protect data. The new prime number is presently too long to be put to any practical purpose, as the currently used prime numbers are only hundred of digits long, and not millions. But, it has prospective future use. 

Content: independent.co.uk