An integer is an optionally signed, arbitrary-length sequence of one or more decimal digits.  The maximum length of an integer is system dependent and can be obtained by using kernelopts(maxdigits).

The Integer(x) constructor function returns

x if x is a positive or negative integer.

symbolic infinity if x is infinity.

undefined if x is a symbolic undefined.

Integer(Re(x)) + I * Integer(Im(x)) if x is of type nonreal.

Otherwise, it returns unevaluated.

The integer 0 does not have a sign (compare the floating-point zeros, +0.0 and -0.0).

In addition to arithmetic operators, some basic functions that operate on integers are:

There are also many other functions for integers in the NumberTheory and combinat packages (including binomial coefficients, Fibonacci numbers, Stirling numbers, Jacobi symbol, and Euler's totient function).