phone number

String of specific numbers that a telephone or cell phone user can dial to reach another telephone or mobile phone. In the US, a phone number consists of 10 numeric digits, and sometimes requires dialing a 1 (the US country code) before the 10 digits. The first 3 digits are the area code, which are unique to a geographical location, and then the remaining 7 digits are unique to each device or user. In instances where a phone number consists of words/letters, the letters correspond to the specific number on the telephone keypad. For example, if a phone number was 555-TESTING, the letter 'T' would correspond to the number 8, the letter 'E' would correspond to the number 3, 'S' to 7, and so on. A person wanting to dial the number 555-TESTING would have to dial 555-837-8464 to achieve their goal.