A safe of a treasure chest can be unlocked with a 5 digit key. The following is known about it. The 4th digit is 4 greater than the second digit, while the 3rd digit is 3 less than the 2nd digit. The 1st digit is thrice the last digit. There are 3 pairs whose sum is 11. Find the number.

Can you find a four digit number based on three clues below?
Clue-1: Its first digit is of no use.
Clue-2: Its second and fourth digit is the mirror image of each other.
Clue-3: The third digit is half the second.