Abner challenges Benny to find out his secret number. On being requested by Benny for some clues, Abner says:

1. It is a 4-digit number.
2. The thousands digit is precisely 5 less than one-sixth of the number formed by the concatenation of its hundreds and tens digit (from left to right).
3. The hundreds digit is precisely 1.8 more than 1/40 of the number formed by the concatenation of its tens and units digits (from left to right).
4. Its tens digit is precisely 2 less than 5/4 times the units digit.

Determine Abner's secret number from the above-mentioned statements.