It is a whole number and it hences a rational number, its a real number as well. the number 0 is niether positive nor negative its displayed as the central number on the number line, so i would consider it as NEUTRAL.
Its a neutral number cause it has no value since its worth nothing at all, when u add it with something the number ur adding it with will be that number instead of 0, (like for ex 2 + 0 = 2) 0 cant be positive since on a number line its not on the right and it cant be negative since its not on the left, so its neutral in the middle.