EBS R12.1.1 Undo Tablespace

Dears

I like to ask you about undo tablespase the size approach to be full around 13,920 MB

Is this healthy for database ?

SQL>  show parameter undo

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
undo_management              string      AUTO
undo_retention                    integer     900
undo_tablespace                 string      APPS_UNDOTS1

SQL> SELECT DISTINCT STATUS, SUM(BYTES), COUNT(*)
  2  FROM DBA_UNDO_EXTENTS GROUP BY STATUS;

STATUS          SUM(BYTES)   COUNT(*)
---------              ----------              ----------
UNEXPIRED     1.3749E+10       1937
ACTIVE            109051904         13
EXPIRED          4587520            40

SQL> select autoextensible from dba_data_files where tablespace_name='UNDOTBS1';

no rows selected

SQL> select autoextensible from dba_data_files where tablespace_name='APPS_UNDOTS1';

AUT
---
NO