The largest prime number yet discovered is 17,425,170 digits long. The new prime number breaks the record of the last one discovered, in 2008, which was only 12,978,189 digits long.
The 17-million digit Mersenne Prime is the result of 2 raised to the 57,885,161 power minus 1.
University of Central Missouri mathematician Curtis Cooper discovered the prime as part of a giant network of volunteer computers devoted to finding primes called the Great Internet Mersenne Prime Search (GIMPS). The program utilizes roughly 360,000 processors making 150 trillion calculations per second.
This prime number is the 48th example of a rare class of primes called Mersenne Primes. First described by French monk Marin Mersenne 350 years ago, Mersenne primes take the form of 2 raised to the power of a prime number minus 1.
After the prime was discovered, it was double-checked by several other researchers using other computers. The new discovery makes Cooper elligible for a $3,000 GIMPS research discovery award.
Large primes can be used for online encryption, and The Electronic Frontier Foundation will award $150,000 to the person who finds a prime with 100 million digits; a $250,000 prize awaits a one billion-digit discovery.