A Carleton University PhD student has played a key role in the recent discovery of the world’s largest-known prime number.
An international team called the Great Internet Mersenne Prime Search — of which Ottawa’s Jeff Gilchrist is a member — discovered the 12.9 million-digit number on August 23.
Gilchrist, 32, independently verified the number using one of the university’s supercomputers over 16 days.
It is the first prime number — a number that can only be equally divided by the number one and itself —ever discovered with more than 10 million digits and qualifies for the Electronic Frontier Foundation Cooperative Computing Award of $100,000 U.S.
“It’s very exciting for me,” said Gilchrist, who is studying systems and computer engineering at Carleton University.
“In the mathematical world, this is like an Olympic event where everyone is trying to beat the last record.”
Discovered by a computing manager at the University of California, the new largest-known prime number — written in shorthand as 243,112,609-1 — beats the last record of 9.8 million digits by more than 3 million digits.
The new record has wiped out six other-record breaking prime numbers that Gilchrist has helped to verify over the years.
“This number’s important because it breaks the 10-million barrier,” said Gilchrist. “It’s a big deal in the mathematical world.
“To get an idea of how large this number really is, if you printed all of the digits in a book, it would be over 3,200 pages long,” he said.
“That would fill the majority of the Harry Potter series of books. I find it fascinating that a number with over 12 million digits cannot be equally divided by another number except one and itself.”
In itself, this particular number is not important.
“It’s more to see what computers are capable of doing with extremely large numbers,” said Gilchrist. “Prime numbers are used in some computer security systems. Some cryptographic algorithms are used for Internet security and e-commerce relies on the difficulty of finding large prime numbers,” he said.
