From the reviews:
“The book under review should succeed very well as a source from which to learn a lot of very beautiful number theory in an accessible way … . This book is clearly a true labor of love and Bordellès has produced an important text and an elegant scholarly work.” (Michael Berg, The Mathematical Association of America, August, 2012)
“The book is essentially self-contained and, in such a manner, a suitable primer for upper-level undergraduates. But also masters-level students and more advanced graduates will find a wealth of fundamental and fascinating arithmetic topics in this panoramic textbook. … It is very gratifying to have an English version of this excellent, textbook of number theory by O. Bordellès, and that in the present, significantly extended and improved form. No doubt, this book will find many interested readers within the international mathematical community.” (Werner Kleinert, Zentralblatt MATH, Vol. 1244, 2012)
“Number theory constitutes a super-subject, a virtual commonwealth of distinctive and semiautonomous disciplines all connected together by a volume of cross-border commerce sufficient to preclude any effective decoupling. … Modern developments that have a reasonably elementary character … appear in a logical way alongside vintage topics. … Replete with novel observations, clever exercises (solved!), and many nice details. Summing Up: Highly recommended. Lower-division undergraduates and above.” (D. V. Feldman, Choice, Vol. 50 (7), March, 2013)
“The author has written an introduction to number theory which starts with elementary questions and quickly advances to more difficult subjects. … At the end of each chapter there is a section containing rich information about recent developments and a list of exercises. The book contains a lot of useful information, and may be of interest also for specialists.” (W. Narkiewicz, Mathematical Reviews, January, 2013)