'No practical use' for 17-million digit prime number
8 February 2013 Last updated at 11:16 GMT
A new prime number, thought to be the largest ever identified, has been discovered by a professor at the University of Central Missouri.
Curtis Cooper used a giant computer network to do the work to find the 17-million digit number - which is a number divisible only by itself and by one.
Speaking to the Today programme about what use the number may be, Mr Cooper said: "I don't know of any practical application of the fact that this number is prime.
"But with that being said, there are some side effects from this process we went through, this idea of taking a big problem and putting out on thousands of PCs and letting them work on the problem, and then finding something at the end."
First broadcast on BBC Radio 4's Today Programme on Friday 8 February 2013.