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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/21005

21005

ZIP 21005 is Aberdeen Proving Ground, Maryland, in Harford County; area codes 667, 443 and 410; Eastern time.

Type
Standard
Time zone
America/New_York
County
Harford
Population
2,202
Coordinates
39.4726, -76.1107
☼ Live from 21005 — Aberdeen Proving Ground, MD

Weather right now

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Local time: —

Where 21005 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 21005
  • 🔢 Type 21005 into a pocket calculator and turn it upside down: SOOIZ — not quite a word, sorry.
  • ➕ As a number, 21,005 = 5 × 4201. Its digits add up to 8, a total 251 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101001000001101
  • 🏠 Its numerical neighbours: 21001 (Aberdeen, MD, 5 mi away) and 21009 (Abingdon, MD, 9 mi away).
  • 🔄 Backwards, 21005 becomes 50012 — and that is a real ZIP code: Ames, IA, 933 miles away.
  • 👥 23 other ZIP codes are made of exactly the same digits (01520, 02051, 02150, 05201, 10025, 10502, …). The farthest-flung twin is 51020 in Galva, IA, 1,026 miles away.
  • 🧭 Farther north than 52% of all ZIP codes, and farther east than 84%.
  • 🎯1,192 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21005 and you would come out at 39.47°S, 103.89°E — 848 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
  • 📏 At 33.4 square miles of land, 21005 is bigger than 48% of ZIP codes — room for about 25 Central Parks.
🌙 The sky over 21005 today
  • Working out the sun…
🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population2,202This ZIP2,202
Households835This ZIP835
Housing units948This ZIP948
Median age33.1This ZIP33.1Maryland39.4US 38.9
Median household income$125,208This ZIP$125,208Maryland$103,678US $80,734
Median gross rent$2,087This ZIP$2,087Maryland$1,705US $1,413
Bachelor's degree or higher55.2%This ZIP55.2%
Mean commute14.7 minThis ZIP14.7 min
Population density66.0 / sq miThis ZIP66.0 / sq mi

Business and tax activity

Business establishments94This ZIP94
Employees3,150This ZIP3,150
Annual payroll$354,826,000This ZIP$354,826,000
Tax returns filed850This ZIP850
Total adjusted gross income$71,610,000This ZIP$71,610,000

Land area

Land area33.35 sq miThis ZIP33.35 sq mi
Water area1.03 sq miThis ZIP1.03 sq mi

Other place names in 21005

Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.

ZIP codes near 21005

ZIPCityDistance
21130 Perryman, MD 4.2 mi
21001 Aberdeen, MD 5.3 mi
21902 Perry Point, MD 6.0 mi
21078 Havre De Grace, MD 6.2 mi
21017 Belcamp, MD 6.6 mi
21610 Betterton, MD 7.6 mi
21903 Perryville, MD 7.8 mi
21009 Abingdon, MD 9.3 mi
21667 Still Pond, MD 9.4 mi
21040 Edgewood, MD 9.7 mi

Find every ZIP code within 10 miles of 21005 →

Questions about this ZIP code

Where is ZIP code 21005?

21005 is in Aberdeen Proving Ground, Maryland, in Harford County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.4726, -76.1107.

What county is 21005 in?

21005 lies in Harford County.

What area code is 21005?

Aberdeen Proving Ground uses area codes 667, 443 and 410, from NANPA's telephone records.

What time zone is 21005 in?

21005 uses America/New_York.

How many people live in 21005?

About 2,202 people live in ZIP code 21005, in 835 households, at 66.0 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 21005?

$125,208 a year, against $103,678 across Maryland.

What ZIP codes are near 21005?

The closest are 21130 (4.2 mi), 21001 (5.3 mi), 21902 (6 mi), 21078 (6.2 mi) and 21017 (6.6 mi).

Is 21005 a PO Box ZIP code?

21005 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “21005 ZIP Code — Aberdeen Proving Ground, Maryland (Harford County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21005

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