0551

0551 is most widely recognized as the telephone area code assigned to Hefei, the capital city of Anhui Province in eastern China. It forms part of China's national system of area codes used to route landline calls to specific cities and regions. In international dialing, calls to Hefei landlines use the format +86 551 followed by the local number, with the leading zero omitted in international contexts.

Domestically within China, calls to Hefei from another city typically use the long-distance dialing sequence 0 551 followed by the local number. When calling from within Hefei itself, callers generally use the local number without the area code. The 0551 area code covers Hefei and its surrounding urban districts as defined by the national telephone numbering plan.

Beyond telecommunications, 0551 may appear as a numeric string in various contexts, such as identifiers or catalog numbers, but it does not have a widely recognized, distinct meaning outside the telephone numbering system. In computing, numbers with leading zeros can be interpreted as octal literals in some programming languages, in which case 0551 can be read as a representation that equates to a different decimal value, depending on the language’s rules.