Prefix Information
The prefix 640 is part of area code 307 serving Cheyenne, Wyoming.
This exchange contains 10,000 possible phone numbers (307-640-0000 through 307-640-9999).
Phone numbers with prefix 640 in area code 307. Location: Cheyenne, Wyoming.
The prefix 640 is part of area code 307 serving Cheyenne, Wyoming.
This exchange contains 10,000 possible phone numbers (307-640-0000 through 307-640-9999).