Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/21792

21792

ZIP 21792 is Unionville, Maryland, in Frederick County; Eastern time.

Type
No street area
Time zone
America/New_York
County
Frederick
Coordinates
39.4748, -77.1855

The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

This ZIP code has no Census tabulation area of its own. Its point falls inside ZCTA 21771, whose figures describe that area — not this ZIP code.

☼ Live from 21792 — Unionville, MD

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Where 21792 is

This ZIP code has no Census tabulation area, so there is no boundary to draw — the marker is its published point location.

★ Weird and wonderful facts about 21792
  • 🔢 Type 21792 into a pocket calculator and turn it upside down: ZGLIZ — not quite a word, sorry.
  • ➕ As a number, 21,792 = 2 × 2 × 2 × 2 × 2 × 3 × 227. Its digits add up to 21, a total 2,594 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101010100100000
  • 🏠 Its numerical neighbours: 21791 (Union Bridge, MD, 4 mi away) and 21793 (Walkersville, MD, 9 mi away).
  • 🔄 Backwards, 21792 becomes 29712 — and that is a real ZIP code: Edgemoor, SC, 385 miles away.
  • 👥 31 other ZIP codes are made of exactly the same digits (12729, 12792, 12927, 12972, 17229, 17922, …). The farthest-flung twin is 97122 in Hebo, OR, 2,381 miles away.
  • 🧭 Farther north than 52% of all ZIP codes, and farther east than 81%.
  • 🎯1,136 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21792 and you would come out at 39.47°S, 102.81°E — 896 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
🌙 The sky over 21792 today
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Source: USGS.

Land area

ZIP codes near 21792

ZIPCityDistance
21762 Libertytown, MD 3.4 mi
21791 Union Bridge, MD 4.0 mi
21776 New Windsor, MD 5.5 mi
21771 Mount Airy, MD 5.7 mi
21774 New Market, MD 6.5 mi
21798 Woodsboro, MD 7.3 mi
21701 Frederick, MD 8.2 mi
21775 New Midway, MD 8.5 mi
21793 Walkersville, MD 8.5 mi
21759 Ladiesburg, MD 8.6 mi

Find every ZIP code within 10 miles of 21792 →

Questions about this ZIP code

Where is ZIP code 21792?

21792 is in Unionville, Maryland, in Frederick County, part of the Washington-Arlington-Alexandria, DC-VA-MD-WV metropolitan area. Its published point location is 39.4748, -77.1855.

What county is 21792 in?

21792 lies in Frederick County.

What time zone is 21792 in?

21792 uses America/New_York.

What ZIP codes are near 21792?

The closest are 21762 (3.4 mi), 21791 (4 mi), 21776 (5.5 mi), 21771 (5.7 mi) and 21774 (6.5 mi).

Is 21792 a PO Box ZIP code?

Possibly. The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

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Cite this page

zipcodes.pro. “21792 ZIP Code — Unionville, Maryland (Frederick County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21792

Machine-readable version of these facts:

curl https://zipcodes.pro/zip/21792.json

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