The number is used in calling a particular telephone WordNet 3.0 & Open English WordNet

A telephone number is a sequence of digits assigned to a landline telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network or other public and private networks. Wikipedia

unique sequence of digits assigned to a telephone subscription Wikidata

A sequence of digits used to reach a particular person on a telephone network. OmegaWiki

A sequence of digits and letters used to register people, automobiles, and various other items. Wiktionary

Sequence of digits and letters used to register people, automobiles, etc. Wiktionary (translation)

A telephone number. Wiktionary

The sequence of digits used to identify a particular destination telephone in a network. Wiktionary