Integer

An integer is any whole number, positive, negative, or 0. More precisely, the set of all integers consists of all natural numbers {1, 2, 3, 4, ...}, their negatives {-1, -2, -3, -4, ...} and 0. A formal definition is that it is the only integral domain whose positive elements are well ordered and in which order is preserved by addition.

An integer may be even (divisible by two) or odd (not divisible by two), positive (more than nothing) or negative (less than nothing), whole (undivided) or fractional (divided into smaller parts), and various other classifications, such as prime (only divisible by itself and one).

Every integer larger than 1 has a unique prime factorizarion.

Some examples of integers: 1, 10/5, 98058493, -87, -3/3, the square root of 9, and 0.

Likewise, the following numbers are not integers: 5/10, the square root of -9, 8.75, and pi.