An Introduction to the Theory of Numbers Hardcover – 21 Mar. 1991

As a retired IT professional who did lots of computational applied maths I am coming back to mathematics and i really like this book.It is easy to read and there are plenty of problems too.Of course it does takes time to read and assimilate each chapter.Lots of other good books out there too and I recommend Rosen as a modern text to compliment this classic.