21764

21764 is a natural number that comes after 21763 and before 21765. It is an even composite number.

In prime factorization terms, 21764 = 2^2 × 5441, where 5441 is a prime number. The number is divisible by 4 but not by 3 or 5. The sum of its digits is 20, so it is not divisible by 3; hence it is not divisible by 9. In binary it is 101010100000100.

As a designation in other contexts, 21764 is used as a United States ZIP code assigned to a specific area. ZIP codes are a part of the postal system used to route mail within the United States.

In astronomy, 21764 may appear as a designation in catalogs for minor planets and other astronomical objects; if a particular object bears this number, it would be listed with additional data such as discovery details and orbital elements.

Beyond mathematics and geography, 21764 can also serve as a general identifier in product catalogs, inventory systems, or datasets. Like many numbers, its use as a code or model number depends on the organization and context.