It is RATIOnal, because it can be written
which is the RATIO of two integers.
It's not a whole number because the whole numbers are 0,1,2,3,4,... and
they are never negative.
It is not a natural number because the natural numbers are 1,2,3,4,5,...
It is an integer. The integers are ...,-5,-4,-3,-2,-1,0,1,2,3,4,5,...
Edwin