SQL & PL/SQL :: Dynamic SQL Returning Clause Into Collection

I have been testing some functionalist, I have been trying to get the updated dept no values into an array and then print the count. But i am getting the following error.

I have implemented, the whole example is to know about 'dynamic sql returning clause into collection'

s@ORCL> select * from t_dept;

DEPTNO DNAME LOC
---------- -------------- -------------
10 comp NEW YORK
20 Compt DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
60 Comp Ahaaa
80 data ab
80 data ab
80 data ab
80 data ab

9 rows selected.

s@ORCL> ed
Wrote file afiedt.buf

1 declare
2 type tp_dept is table of number;
3 arr_dept tp_dept;
4 begin
5 execute immediate q'['update t_dept set dname = 'Pointers' where deptno = 80 returning deptno into :out]'
6 returning into arr_dept;
7 dbms_output.put_line('The count is '||arr_dept.count);
8* end;
s@ORCL> /
returning into arr_dept;
*
ERROR at line 6:
ORA-06550: line 6, column 19:
PLS-00597: expression 'ARR_DEPT' in the INTO list is of wrong type
ORA-06550: line 5, column 4:
PL/SQL: Statement ignored