Toad + oracle + hexadecimal 4,1XXXXXXXX52E15 (41XXXXXXXX5198)

Currently executing the following query:

SELECT
     SOL_RDDDETALLEREPROGRAMACION.operacion
  FROM evaluacion.SOL_RDDDETALLEREPROGRAMACION, 
       CREDITO.PRODUCTO P, 
       CREDITO.CUOTA C,
       CREDITO.CREDITO CA
  WHERE SOL_RDDDETALLEREPROGRAMACION.solicitud = 12345678 AND
        CA.credito(+) = SOL_RDDDETALLEREPROGRAMACION.operacion AND                        
        P.codigo (+) = SOL_RDDDETALLEREPROGRAMACION.subproducto AND
        C.credito (+) = SOL_RDDDETALLEREPROGRAMACION.operacion AND
        C.estado (+) < 0;

The OPERATION field comes with the hexadecimal format: 4,1XXXXXXXX52E15. issue that is solved by changing the line SOL_RDDDETALLEREPROGRAMACION.operacion to TO_CHAR(SOL_RDDDETALLEREPROGRAMACION.operacion) .

The question is, is there any other way than to add a TO_CHAR .