21404

21404 is a five-digit number that appears in several independent coding systems. As a numeric string, it serves as an identifier in postal geography, astronomy, and various industries. In the postal system of the United States, five-digit ZIP codes designate specific delivery routes; 21404 is within this regime and would designate a particular locality for mail routing and address standardization.

In astronomy, 21404 is the numeric designation of a minor planet catalogued by the Minor Planet Center, indicating it is a confirmed asteroid in the solar system. As with many numeric identifiers, the same sequence is used by manufacturers and institutions to label models, parts, or catalog entries, so 21404 may appear as a product number, component identifier, or reference in a dataset or inventory system. In data science and bibliographic catalogs, 21404 can ensure a consistent identifier across records, enabling cross-referencing between datasets.