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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/21056

21056

ZIP 21056 is Gibson Island, Maryland, in Anne Arundel County; area codes 443, 410 and 667; Eastern time.

Type
Standard
Time zone
America/New_York
County
Anne Arundel
Population
291
Coordinates
39.0790, -76.4362
☼ Live from 21056 — Gibson Island, MD

Weather right now

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Local time: —

Where 21056 is

Approximate ZIP boundary (Census ZCTA 2020). ZIP codes are mail routes, not areas, so the shape shown is the Census tabulation area that approximates it.

★ Weird and wonderful facts about 21056
  • 🔢 Type 21056 into a pocket calculator and turn it upside down: gSOIZ — not quite a word, sorry.
  • ➕ As a number, 21,056 = 2 × 2 × 2 × 2 × 2 × 2 × 7 × 47. Its digits add up to 14, a total 1,416 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101001001000000
  • 🏠 Its numerical neighbours: 21054 (Gambrills, MD, 14 mi away) and 21057 (Glen Arm, MD, 26 mi away).
  • 🔄 Backwards, 21056 becomes 65012, which is not a ZIP code at all.
  • 👥 67 other ZIP codes are made of exactly the same digits (01256, 01526, 01562, 02156, 02561, 02651, …). The farthest-flung twin is 56210 in Barry, MN, 1,117 miles away.
  • 🧭 Farther south than 50% of all ZIP codes, and farther east than 84%.
  • 🎯1,179 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21056 and you would come out at 39.08°S, 103.56°E — 848 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 55m of daylight. Shortest: 9h 25m.
  • 📏 At 1.4 square miles of land, 21056 is bigger than 10% of ZIP codes — room for about 1.0 Central Parks.
🌙 The sky over 21056 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population291This ZIP291
Households145This ZIP145
Housing units306This ZIP306
Median age66.6This ZIP66.6Maryland39.4US 38.9
Median household income$250,000+This ZIP$250,000+Maryland$103,678US $80,734
Median home value$2,000,000+This ZIP$2,000,000+Maryland$419,900US $332,700
Bachelor's degree or higher93.1%This ZIP93.1%
Population density211.5 / sq miThis ZIP211.5 / sq mi

Business and tax activity

Business establishments6This ZIP6
Employees133This ZIP133
Annual payroll$8,147,000This ZIP$8,147,000

Land area

Land area1.38 sq miThis ZIP1.38 sq mi
Water area0.25 sq miThis ZIP0.25 sq mi

ZIP codes near 21056

ZIPCityDistance
21122 Pasadena, MD 3.7 mi
21012 Arnold, MD 3.9 mi
21409 Annapolis, MD 4.2 mi
21402 Annapolis, MD 6.5 mi
21146 Severna Park, MD 6.6 mi
21405 Annapolis, MD 6.9 mi
21404 Annapolis, MD 7.6 mi
21052 Fort Howard, MD 8.7 mi
21401 Annapolis, MD 8.9 mi
21032 Crownsville, MD 9.7 mi

Find every ZIP code within 10 miles of 21056 →

Questions about this ZIP code

Where is ZIP code 21056?

21056 is in Gibson Island, Maryland, in Anne Arundel County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.0790, -76.4362.

What county is 21056 in?

21056 lies in Anne Arundel County.

What area code is 21056?

Gibson Island uses area codes 443, 410 and 667, from NANPA's telephone records.

What time zone is 21056 in?

21056 uses America/New_York.

How many people live in 21056?

About 291 people live in ZIP code 21056, in 145 households, at 211.5 people per square mile. These are American Community Survey 5-year estimates for the ZIP Code Tabulation Area, not a headcount.

What is the median household income in 21056?

$250,000+ a year, against $103,678 across Maryland.

What ZIP codes are near 21056?

The closest are 21122 (3.7 mi), 21012 (3.9 mi), 21409 (4.2 mi), 21402 (6.5 mi) and 21146 (6.6 mi).

Is 21056 a PO Box ZIP code?

21056 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “21056 ZIP Code — Gibson Island, Maryland (Anne Arundel County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21056

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