Area code and exchange code is assigned to every constituent of city in the United States. The area and exchange codes of the telephone can be used to find information about a region. Area code 620 and exchange code 820 is assigned to Parsons. The latitude and longitude corresponding to 37.34 and -95.26 can be used to find an area on the map. Southwestern Bell - Ksoperates most of the land lines in United States.