Number theory (or
arithmetic or
higher arithmetic in older usage), is a branch of
pure mathematics devoted primarily to the study of the
integers. It is sometimes called "The Queen of Mathematics" because of its foundational place in the discipline.
[1] Number theorists study
prime numbers as well as the properties of objects made out of integers (e.g.,
rational numbers) or defined as generalizations of the integers (e.g.,
algebraic integers).