11521

11521 is a natural number that sits between 11520 and 11522. It is most commonly encountered in mathematical and coding contexts, where it serves as a concrete example of a five-digit integer with interesting factorization properties.

In number theory, 11521 is a composite number with prime factorization 41 × 281. This makes it a semiprime, having exactly two prime factors counting multiplicity. The sum of its digits is 10, so it is not divisible by 3 or 9, and it ends in 1, so it is not divisible by 2 or 5. In binary, 11521 is 10110100000001, and in hexadecimal it is 0x2D01. The number is odd, not a perfect square, and its divisors are 1, 41, 281, and 11521.

In postal terms, 11521 is used as a five-digit ZIP code in the United States to designate a specific geographic area within the national postal system. Like other ZIP codes, it is part of an addressing scheme that helps route mail and packages efficiently.

Beyond mathematics and mailing, 11521 may appear as a catalog, model, or reference number in various databases, inventories, or product records. As a standalone integer, it has no globally unique meaning beyond these contextual uses, but its mathematical properties and coding role illustrate how five-digit numbers can carry multiple, distinct significances in different domains.