Decimal para Hexadecimal

CREATE OR REPLACE FUNCTION dec2hex (N in number) RETURN varchar2 IS
  hexval varchar2(64);
  N2     number := N;
  digit  number;
  hexdigit  char;
BEGIN
  while ( N2 > 0 ) loop
     digit := mod(N2, 16);
     if digit > 9 then 
       hexdigit := chr(ascii('A') + digit - 10);
     else
       hexdigit := to_char(digit);
     end if;
     hexval := hexdigit || hexval;
     N2 := trunc( N2 / 16 );
  end loop;
  return hexval;
END dec2hex;
/

SQL> SELECT dec2hex(44978)  FROM dual;

DEC2HEX(44978)
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AFB2