← Area code 606
606-491 phone numbers
Numbers 606-491-0000 to 606-491-9999 are assigned to Twilio International, Inc. in Olive Hill, KY. 4 of its ten thousand-number blocks are assigned to other carriers (number pooling).
Not assigned to any carrier: 606-491-2xxx, 606-491-3xxx, 606-491-5xxx, 606-491-6xxx, 606-491-7xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.