The Clay Mathematical Institute is a non-profit, private foundation from Cambridge Massachusetts. Their goal is to increase and disseminate mathematical knowledge. They give out research grants, awards and many other academic incentives for people to study math. However, one of the most interesting ones is called the Millennium Prize Problems.
The Millennium Prize Problems are a group of 7 mathematical problems that the institute set up in the year 2000 (hence, the millennium part of it). They stipulated that whoever was able to solve each of the problems would receive $1,000,000 from the institute. As you can imagine by the large reward, the problems are pretty tough to solve.
As of now, only one of the seven problems has been solved. The Poincaré conjecture was solved by Grigori Perelman, a Russian mathematician, in 2010. He declined the award. So how are your skills? Take a look a the problems and get working!