SQL & PL/SQL :: Oracle Date Conversion Errors

I am having a strange issue with date conversion. The errors encountered are :

PLS-00382: expression is of wrong type
PLS-00306: wrong number or types of arguments in call to '>'

The situation or test case is as follows:

create table sand_programs(prog_code varchar2(20), prog_end_dt date);

create table sand_program1(prog_code varchar2(20), filing_date number(15));
Result : Both the tables are created.

Now I create a procedure below as mentioned, to check if the filing_date is greater than the prog_end_dt or not.If the filing_date is greater than prog_ end_dt, then it should go to the 1st "dbms_output.put_line" message else it should go to the 2nd "dbms_output.put_line" message.

Here's my procedure:

create or replace procedure test_sand(p_program_cd in number) is
v_prog_end_dt date;
v_filing_date number;
begin
[code]....