Sierpinski W. Elementary Theory of Numbers 2ed 1988

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Since the publication of the first edition of this work, considerable progress has been made in many of the questions examined. This edition has been updated and enlarged, and the bibliography has been revised. The variety of topics covered here includes divisibility, diophantine equations, prime numbers (especially Mersenne and Fermat primes), the basic arithmetic functions, congruences, the quadratic reciprocity law, expansion of real numbers into decimal fractions, decomposition of integers into sums of powers, some other problems of the additive theory of numbers and the theory of Gaussian integers.
Author's Preface.
Editor's Preface.
Divisibility and indeterminate equations of first degree.
Diophantlne analysis of second and higher degrees.
Prime numbers.
Number of divisors and their sum.
Congruences.
Euler's totient function and the theorem of Euler.
Representation of numbers by decimals in a given scale.
Continued fractions.
Legendre's symbol and Jacobi's symbol.
Mersenne numbers and Fermat numbers.
Representations of natural numbers as sums of non-negative kth powers.
Some problems of the additive theory of numbers.
Complex integers