Is there only one whole number that is not a natural number?

Answer 1

A "whole number" is called an integer < Lat. integer = whole.

Natural numbers are sometimes defined as the positive integers and sometimes 0 is included in the definition. It depends on the situation whether or not 0 is considered a natural numbers (so there are two possible definitions of the natural numbers). Both definitions have pros and cons. None is "better" or "more correct" than the other.

Your question, therefore, seems to center around the number 0.

However, the answer is: no.

Because all negative integers are not natural numbers. There are an infinite number of negative integers.

Also, if you include Gaussian integers (which are of the form x + iy, where x and y are integers and i is the imaginary number), then all Gaussian integers with y <> 0 or x<0 are not natural numbers.