title: ORA-01722- Invalid Number
body: <p>I have a query in the package throwing error</p>
  
  <blockquote>
    <p><strong>ORA-01722</strong> : invalid number.</p>
  </blockquote>
  
  <p>I tried many ways but no luck.</p>
  
  <pre><code>select h.column  
    from table1 h,table2 c 
   where c.created_date='17-MAY-17' 
     and nvl(c.acct_nmbr,0)=nvl(to_number(h.v_acct_num),0) 
  </code></pre>
  
  <ul>
  <li><code>c.acct_nmbr</code> is of <code>NUMBER(19,0)</code></li>
  <li><code>h.v_acct_num</code> is of <code>varchar2(4000 byte)</code></li>
  </ul>
  
  <p>Please suggest me the solution</p>