The area code (phone code) 06133 is assigned to 4 locations in Germany. Mainly you reach landlines in Nierstein (Rheinland-Pfalz).
Note for calls from abroad: In addition to the German country code (+49 or 0049) you can omit the foregoing zero of the dialling code for Nierstein. So you can dial +496133... and add the number of the phone line you want to reach.