Mathematicians at the University of California could be in line for a $100,000 prize for finding a new prime number, which has 13 million digits.
Prime numbers can be divided only by themselves and one, such as three and seven.
The prize was set up by the Electronic Frontier Foundation to promote co-operative computing on the Internet.
The team from the University of California at Los Angeles (UCLA) found the new number by linking 75 computers and harnessing their unused power.
This enabled them to perform the enormous number of calculations needed to find and verify a new prime.