Number theory

Number theory is a branch of mathematics primarily devoted to integers and arithmetic functions. It studies prime numbers, rational numbers, algebraic integers and equations involving integers. Its questions can also be approached through analytical objects such as the Riemann zeta function, or through the approximation of irrational numbers by fractions. One of the oldest branches of mathematics, number theory includes problems that may be simple to state but difficult to solve. Prime numbers later became a basis for public-key cryptography algorithms.

Primary subject

Integers and arithmetic functions

Studies

Prime numbers and properties of objects constructed from or generalizing integers

Application

Public-key cryptography algorithms, including RSA