Integer Integer 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, , and are not. The set of integers consists of zero (), the positive natural numbers (, , , …), 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 ("") or blackboard bold formula_1 (Unicode U+2124 ℤ) standing for the German word "Zahlen" (, "numbers"). The integers form
Radical of an integer Radical of an integer In number theory, the radical of a positive integer "n" is defined as the product of the distinct prime numbers dividing "n". Each prime factor of "n" occurs exactly once as a factor of this product: The radical plays a central role in the statement of the abc conjecture. Radical numbers for the first few positive integers are For example, and therefore The function formula_4 is multiplicative (but not completely multiplicative). The radical of any integer "n" is the largest square-free divisor of "n" and so also described as the square-free kernel of "n". There is