ABSTRACT
Number theory is one of the oldest branches of mathematics and deals principally with the properties of the integers, the simplest kinds of numbers. The main result proved in this chapter is that every natural number greater than one can be written as a product of powers of primes, a result known as the fundamental theorem of arithmetic. This shows that the primes are the building blocks, or atoms, from which all natural numbers are constructed. The primes are still the subject of intensive research but their theory goes right back to Euclid’s Elements.
