| each digit of the number is in octal, not decimal. You can calculate and interpret them as follows:
First digit is owner permissions
Second digit is group permissions
Third digit is world permissions
The value of each digit is the sum of the permissions granted to that class of user:
4 - read permission
2 - write permission
1 - execute permission
so 544 gives read and execute permissions to the owner, and read permissions to the group and to the world.
For a more detailed explanation see the manpage | 
