Four digit number based on three clues - Math Riddle

848

Explanation :  
Clue 1: Its first digit is of no use.
The digit '0' at the start of the number is of no use.

Clue 2: Its second and fourth digit is the mirror image of each other.
The number '8' is the only digit that is the mirror image of itself.

Clue 3: The third digit is half the second.
4 is half of 8