This book is aimed at students of the exact sciences, mathematics teachers, and participants in ASEPs and Olympiads competitions.

It is a comprehensive textbook on classical Number Theory. The theory is developed thoroughly and is accompanied by numerous examples and applications that clarify all concepts in detail.

The chapters included are:
1) Euclidean division of integers
2) Divisibility of integers
3) Greatest common divisor - Least common multiple
4) Prime numbers
5) Equivalences
6) Arithmetic and multiplicative functions
7) Polynomial equivalences and quadratic residues
8) Diophantine equations.

Each chapter proposes a large number of exercises of increasing difficulty, for which brief solutions or hints for their solution are provided at the end of the book.

- For students of the exact sciences
- For mathematics teachers
- For ASEPs and Olympiads competitions