“Collection of problems on number theory” is a fascinating and informative publication created under the authorship of Oleg Nikolayevich Vasilenko and Alexander Ivanovich Galochkin .. This book is not just a set of problems, but a whole world in which readers are immersed, seeking to understand and master one of the most interesting and deep areas of mathematics - number theory. The theory of numbers is known to study the properties of integers, their relationships and regularities.. In this collection you will find a variety of tasks that will help you not only to test your knowledge, but also to deepen your understanding of this fascinating discipline. Each task is accompanied by detailed solutions and comments, which makes the learning process more accessible and understandable. The authors strive not only to offer readers ready-made answers, but also to develop their analytical thinking, to teach them to approach problems from different angles. The book will be of interest to both students studying mathematics and teachers who are looking for quality materials to prepare their lessons. It is suitable for high school students preparing for Olympiads and competitions, as well as for anyone who wants to deepen their knowledge in the field of mathematics. If you are interested in puzzles and logical tasks, then this collection will be a real find for you. The topics raised in the book cover a wide range of issues, ranging from simple properties of numbers to more complex concepts, such as Fermat's theorem and the distribution of prime numbers. The authors focus on the practical application of number theory in various fields of science and technology, which makes the material especially relevant in the modern world. You will be able to see how abstract mathematical concepts find their application in cryptography, computer science, and even economics. The style of the authors is distinguished by clarity and accessibility, which makes complex mathematical ideas understandable to a wide audience. Oleg Nikolayevich Vasilenko and Alexander Ivanovich Galochkin are experienced teachers and researchers who not only perfectly possess the subject, but also know how to convey it to the reader. Their previous work is also noteworthy, as they have already established themselves as authors of quality teaching aids and scientific articles. If you are looking for books on mathematics, number theory, problems to prepare for the Olympics or just want to improve your skills in solving logical problems, the "Collection of problems in number theory" will be a great addition to your library. This edition will help you not only to develop mathematical thinking, but also to give many hours of fascinating pastime. Do not miss the opportunity to immerse yourself in the world of numbers and their mysteries that await you in the pages of this book. Discover the theory of numbers from a new side and allow yourself to become a master in solving mathematical problems!