What kind of number is -5? is it rational or something like that?

The number -5 is anything but natural number.
It is an integer (Z) ,a rational number (Q) and a real number (R) .

ANSWER
-5 is a real number, a rational number, and an integer

EXPLANATION
Rational number are numbers which you can write as a quotient of two integers. Integers are non-decimal numbers that can be positive or negative. We can therefore write -5 as -5 divided by 1 (-5/1) and thus classify -5 as rational.

In fact, you can classify -5 into other categories.

-5 is all of the following
⇒ it is a real number
⇒ it is a rational number
⇒ it is an integer

Whole numbers can be considered as {0, 1, 2, 3, ...}
Natural numbers can be considered as {1,2,3,...}

so -5 is not a whole or natural number.