This book is an expanded version of a series of lectures for graduate students on elementary number theory. It simply assumes knowledge of the most basic arithmetic principles (divisibility properties, greatest common divisor, etc.).
Compositions and Partitions, Arithmetic Functions, Prime Number Distribution, Irrational Numbers, Congruences, Diophantine Equations, Combinatorial Number Theory, and Number Geometry are some of the topics covered. The material is finished with three sections of problems (which comprise both exercises and unresolved problems).