One quesion about a mathmatical trick in SQL

Hi All,

The SQL is:

SELECT chr(to_char(bitand(p1,-16777216))/16777215)||
         chr(to_char(bitand(p1, 16711680))/65535) "Lock",
         to_char( bitand(p1, 65535) )    "Mode"
    FROM v$session_wait
   WHERE event = 'enqueue'
  ;

It seems to seperate high ends and the lower ends of a number. I know a little about bitand, which dose  'bit and' operation. But I'm completely confused by the 'division sign'.

Could some help expound this to me, please?

Thank you very much.
Leon