maxbytes results question for autoextend of unlimited on tablespaces

 I set my datafiles to autoextend with maxsize of unlimited. Why is it I get the following number, in scientific notation, for the maxbytes column of the dba_data_files table?
SQL>
SQL> select maxbytes from dba_data_files;

  MAXBYTES
----------
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11

  MAXBYTES
----------
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11

  MAXBYTES
----------
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11

  MAXBYTES
----------
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11
1.3744E+11

44 rows selected.