Another champion for that title might be Both formulas were derived by Bernhard Riemann in his seminal 1859 paper '' Über die Anzahl der Primzahlen unter einer gegebenen Grösse '' ( `` On the Number of Prime Numbers less than a Given Quantity '' ) , one of the milestones in the development of analytic number theory - the branch of mathematics that studies prime numbers using the tools of mathematical analysis .
This was in 1859 paper '' Über die Anzahl der Primzahlen unter einer gegebenen Grösse '' ( `` On the Number of Prime Numbers less than a Given Quantity '' )