- An integer is a number that can represented without a decimal or fraction part
- An integer could be negative, positive, or 0
- Set Notation: \Zeta =\left\{ ...,-5,-4,-3,-2,-1,0,1,2,3,4,5,... \right\}
- As indicated by the ellipses (…), there are an infinite number of integers
- An integer is a rational number
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| The Zahlen symbol, often used to denote the set of all integers (see List of mathematical symbols) | |
An integer (from the Latin integer meaning "whole") is a number that can be written without a fractional component. For example, 21, 4, 0, and −2048 are integers, while 9.75, 5+1/2, and √2 are not.
The set of integers consists of zero (0), the positive natural numbers (1, 2, 3, ...), also called whole numbers or counting numbers, and their additive inverses (the negative integers, i.e., −1, −2, −3, ...). The set of integers is often denoted by a boldface Z ("Z") or blackboard bold (Unicode U+2124 ℤ) standing for the German word Zahlen ([ˈtsaːlən], "numbers").
Z is a subset of the set of all rational numbers Q, in turn a subset of the real numbers R. Like the natural numbers, Z is countably infinite.
The integers form the smallest group and the smallest ring containing the natural numbers. In algebraic number theory, the integers are sometimes qualified as rational integers to distinguish them from the more general algebraic integers. In fact, the (rational) integers are the algebraic integers that are also rational numbers.