423 Cleveland and surrounding area.
Dayton, Tennessee, is in area code 423.
Yes, there is a telephone directory for area code 901, which is the area around Memphis, Tennessee.
Area code 731 is in that famous part of North Carolina called "western Tennessee." It includes Jackson, TN, but not Memphis.
Area codes are for states and the cities within them. The area code (865) is for part of the state of Tennessee and covers 62 cities. That is at least 62 zip codes if not more.
the area code
There is no area code 621 in North America (USA, Canada, etc.).
The 615 area code includes Tennessee cities such as Nashville and Knoxville. A complete list of counties served by this particular area code can be found on Wikipedia.
Area code 931 covers parts of central and eastern Tennessee in the United States. It includes cities such as Clarksville, Cookeville, and Lebanon. The area code was established in 1997 as a split from area code 615.
The country code for the US (and also Canada and several nearby islands) is +1. There are six area codes in Tennessee: 423, 615, 731, 865, 901, and 931.
216 is an original US code dating from 1947. It covers Cleveland in Ohio.
Area code 731 is western Tennessee, excluding the Memphis metro area. It includes Jackson, Ripley, Brownsville, Bolivar, Paris, Lexington, and Savannah.
The ZIP code for Gatlinburg, Tennessee is 37738.