This course provides an introduction to the theory of numbers. Here we will examine classical issues involving prime numbers, divisibility, and the general structure of numbers. Various applications and consequences will be discussed. In addition, we shall examine the real and complex numbers and also numbers which are neither real nor complex. These new numbers are called p-adic numbers and are very interesting and important. Although many of these issues go back to the dawn of humanity, here we will take a very modern approach and use new techniques to investigate the issues at hand. Evaluation will be based primarily on performance on assignments, projects, and exams. Prerequisites: Mathematics 211 or 251, or permission of instructor.