51521

51521 is a natural number that lies between 51520 and 51522. It is an odd five-digit integer. In mathematical terms, 51521 is a prime number, meaning it has no positive divisors other than 1 and itself. The square root of 51521 is approximately 227.2, so confirming its primality requires checking prime divisors up to 227. Its digit sum is 14, which indicates it is not divisible by 3, and since it does not end in 0 or 5, it is not divisible by 2 or 5. These properties make 51521 a notable example of a five-digit prime number in basic number theory.

In geography and postal contexts, 51521 is also a United States ZIP code. It is assigned to a region in western Iowa for mail delivery within the U.S. Postal Service system. ZIP codes in this range are used to identify geographic areas and facilitate sorting and routing of mail, often covering rural municipalities as well as small towns. The 51521 designation helps local postal operations determine service areas and delivery routes.

Beyond mathematics and mailing, 51521 may appear in various contemporary contexts as a code, model number, or identifier in products and systems. As with many five-digit numbers, its primary public references are typically mathematical and postal, with occasional usage in cataloging or inventory.