The problem is that the hillshade raster has a zfactor of 1.4 and for hydrological tool I need the real data. I tryed to divide the whole raster with raster-calculator with a factor of 1.4 but it cannot creat the same original data. Is there any tool for doing that?
There isn't. When one generates a hillshade raster, the height information is transformed into slope information, and that into a hypothetical illumination information. It is meant to mimick how the terrain would look like given a light source at X degrees from the horizon and Y azimuth (information you need to provide in order to generate it). This whole process is lossy, you don't retain any information from the previous steps.
If you wish to read more about how it's generated, you can do so here.