The beginning of the largest prime number known to man, discovered by Curtis Cooper. You can see the entire number -- more than 17 million digits long -- here (warning: file make take a while to load). - 

A mathematician has discovered the largest prime number known to man. It's got 17 million digits. And the lucky discoverer? Dr. Curtis Cooper, a professor of math and computer science at the University of Central Missouri.

He admits: "there's really no practical application" for his discovery. But he compares the search to an art form and says "in a lot of ways, mathematics and art are pretty closely related."

Due to the length of the number, he hasn't read all the digits. But he does say the first digit is a 5 and the last digit is a 1. See the full number here (warning: the page may take a while to load).

Follow Kai Ryssdal at @kairyssdal