Summary: The article gives a brief outline of the history of the department of Number Theory of MSPU from its creation to the present. In connection with the 150-th anniversary of Moscow State Pedagogical University, a short overvew about the main milestones in history, leading specialists, scientific and educational activities of one of the oldest departments of the Institute of Mathematics and Informatics (until 2018 – the Faculty of Mathematics) of Moscow State Pedagogical University (until 1990 – Moscow State Pedagogical Institute named after V. I. Lenin) is presented.