Johann Carl Friedrich Gauss (1777 – 1855)

was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes referred to as the Princeps mathematicorum (Latin for '"the foremost of mathematicians"') and "the greatest mathematician since antiquity".

Among other things, Gauss discovered the pattern followed by the distribution of prime numbers. And he succeeds in constructing a regular seventeen-gon just with a compass and ruler for the first time. Using a method he invented, he calculates the orbit of the celestial body. The Gauss quadrature, the Gauss integral theorem, Gauss curvature, Gauss normal distribution and much more are named after him.

Carl_Friedrich_Gauss

Georg Friedrich Bernhard Riemann (1826 – 1866)

was a German mathematician who made contributions to analysis, number theory, and differential geometry.

The Riemann Hypothesis is one of the millennium problems:

Riemann Hypothesis

The Clay Institute has pledged a US$1 million prize for the first correct solution to each millennium problem. .