Prefix Information

The prefix 640 is part of area code 406 serving Billings, Montana.

This exchange contains 10,000 possible phone numbers (406-640-0000 through 406-640-9999).

Browse Numbers in This Prefix

406-640-0000-0999 406-640-1000-1999 406-640-2000-2999 406-640-3000-3999 406-640-4000-4999 406-640-5000-5999 406-640-6000-6999 406-640-7000-7999 406-640-8000-8999 406-640-9000-9999

Sample Numbers

(406) 640-0000 (406) 640-1234 (406) 640-2000 (406) 640-3333 (406) 640-4444 (406) 640-5555 (406) 640-6000 (406) 640-7777 (406) 640-8888 (406) 640-9999