Number

Integer

A whole number — positive, negative or zero. No fractions or decimals.

Definition

The integers are: ..., −3, −2, −1, 0, 1, 2, 3, ... The set is denoted ℤ. Integers include negatives. Natural numbers are the positive integers (some definitions include 0).

Example

−5, 0, 7 are all integers. 2.5 and ¾ are not.

Common confusion

Integers are sometimes confused with natural numbers (positive integers only) or with rationals (any fraction).

Related terms

Rational number

A number you can write as a fraction p/q where p and q are integers and q ≠ 0.

Irrational number

A number that cannot be written as a fraction of two integers — its decimal goes on forever without repeating.

Prime number

A whole number greater than 1 whose only factors are 1 and itself.

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