decimal to hexa

Hi,
I want to convert decimal to hexa for hexa being as large as upto 32 digits.How can i do this.This means my decimal will be more bigger.I know how to convert from dec to hex but how can it be done for such large value.
Thanks,
Nishant.

SQL> select to_char(106,'XXXXXXXXX') from dual;

TO_CHAR(10
----------
6A

SQL>

Thanks !!
If i want hexa back to that big number ?
Take care,
Nishant

The other way around:

Code:

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SQL> select to_number('F','XXXXXXXXX') from dual;

TO_NUMBER('F','XXXXXXXXX')
--------------------------
                        15

SQL>

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