A whole number is defined as a positive integer (i.e., a value with no decimal or fractional part). However, in practice, most people consider negative integers to be whole numbers as well.
Yes, when they are decimals, it is not considered a whole number.
Integers
6 is a whole number -47.03 is a negative number -179 is a negative whole number
Yes. ...-3,-2,-1,0,1,2,3... are all whole numbers. Whole numbers are any numbers that aren't a fraction and that includes negative numbers.