020

020 is a numeral used in several different contexts, so its meaning depends on the domain. In standard decimal notation, 020 is simply the value 20, with the leading zero often used for formatting or alignment rather than indicating a different value.

In computing, leading zeros can denote octal (base-8) literals in many programming languages. There, 020 is interpreted as octal twenty, which equals decimal 16. This usage appears in languages such as C and C++, and in JavaScript in older or non-strict modes. In contrast, many modern languages (for example Python 3) disallow leading-zero octal literals and require explicit prefixes like 0o.

In Unix-like operating systems, numbers used to specify file permissions can also be written in octal. The three-digit octal 020 would mean owner permissions 0, group permissions 2 (write), and others 0. Thus it represents a permission set where only the group has write access, in octal notation.

In telecommunications, 020 is the London area code for United Kingdom landlines. Domestic numbers appear as 020 xxxx xxxx, while international dialing format is +44 20 xxxx xxxx, with 44 being the country code for the United Kingdom and 20 the area code for London.

As a plain string, 020 is often used for padding, identifiers, or formatting in various datasets. Its interpretation is not fixed and is determined by the conventions of the specific system or protocol in which it appears.