Basic treatment, incorporating language of abstract algebra and a history of the discipline. Topics include unique factorization and the GCD, quadratic residues, number-theoretic functions and the distribution of primes, sums of squares, quadratic equations and quadratic fields, diophantine approximation, more. Includes many problems. Bibliography. Advanced undergraduate-beginning graduate-level. 1977 edition.
Here's a sample of other books in this Dover category
Number Theory and Its History by Oystein Ore Unusually clear, accessible introduction covers counting, properties of numbers, prime numbers, Aliquot parts, Diophantine problems, congruences, much more. Bibliography.
Elementary Theory of Numbers by William J. LeVeque Superb introduction to Euclidean algorithm and its consequences, congruences, continued fractions, powers of an integer modulo m, Gaussian integers, Diophantine equations, more. Problems, with answers. Bibliography.
Number Theory by George E. Andrews Undergraduate text uses combinatorial approach to accommodate both math majors and liberal arts students. Covers the basics of number theory, offers an outstanding introduction to partitions, plus chapters on multiplicativity-divisibility, quadratic congruences, additivity, and more
Introduction to the Theory of Numbers by Harold N. Shapiro Starting with the fundamentals, this text advances to an intermediate level. Geared toward advanced undergraduates and graduate students, it covers congruence, counting problems, and prime number theory. 1983 edition.
The Number System by H. A. Thurston This book explores arithmetic's underlying concepts and their logical development, in addition to a detailed, systematic construction of the number systems of rational, real, and complex numbers. 1956 edition.
Elementary Number Theory: Second Edition by Underwood Dudley Written in a lively, engaging style by the author of popular mathematics books, this volume features nearly 1,000 imaginative exercises and problems. Some solutions included. 1978 edition.
History of the Theory of Numbers, Volume III: Quadratic and Higher Forms by Leonard Eugene Dickson This 3rd volume in the series History of the Theory of Numbers presents material related to Quadratic and Higher Forms. The investigations deal with the most advanced parts of the theory of numbers. 1919 edition.
An Introduction to the Approximation of Functions by Theodore J. Rivlin This text provides an introduction to methods of approximating continuous functions by functions that depend only on a finite number of parameters — an important technique in the field of digital computation. 1969 edition.