# A new prime number with a staggering, 22 million digits sets record

A professor at a Missouri university has found the largest prime number known to humankind.

Researchers have found a new prime number, now the largest one known to humankind.

Prime numbers are not divisible by any number but one and itself. Examples include one, three, five, seven, and 13. They are presumably infinite but the higher you go, the fewer there are.

This latest number, with more than 22 million digits was found by a computer at the University of Central Missouri as part of the Great Internet Mersenne Prime Search (GIMPS), a global project to find a type of large prime numbers.

The discovered prime number is too long to write out. Instead, it’s written as 2^74,207,281-1, or two, multiplied by itself 74,207,281 times, minus one.

It was discovered by Curtis Cooper, one of thousands of GIMPS volunteers, the project said. The new finding coincides with GIMPS’ 20th anniversary. The previous record of the highest known prime number was found three years ago – Jan. 25, 2013. It was 2 to the power of 57,885,161 minus 1, a figure more than 17 million digits long.

“The new prime number is a member of a special class of extremely rare prime numbers known as Mersenne primes. Mersenne primes were named for the French monk Marin Mersenne, who studied these numbers more than 350 years ago,” the GIMPS project wrote in a statement. “There are only 49 known Mersenne primes. GIMPS, founded in 1996, has discovered the last 15 Mersenne primes.”

Prime numbers play an important role in computer encryption. They ensure the safety of online banking, shopping, private messaging, and other online procedures are safe, but current encryption only uses prime numbers that are hundreds of digits long, not millions.

The record is the fourth one for Dr. Cooper, and took 31 days to calculate on a computer. It’s eligible for a $3,000 discovery award.