This file is password protected.

The password is a nine digit number.  None of its digits repeat themselves.
Its second digit is five less than its last digit.
Its eighth digit is two more than its seventh digit.
Its fourth digit is six less than its third digit.
Its seventh digit is three more than its fourth digit.
Its third digit is double its second digit.
Its first digit is eight less than its last digit.
Its sixth digit is half its fifth digit.