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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/20634

20634

ZIP 20634 is Great Mills, Maryland, in St. Mary's County; Eastern time.

Type
Standard
Time zone
America/New_York
County
St. Mary's
Metro area
Lexington Park, MD
Population
7,088
Coordinates
38.2417, -76.4983
☼ Live from 20634 — Great Mills, MD

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Where 20634 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 20634
  • 🔢 Type 20634 into a pocket calculator and turn it upside down: hEgOZ — not quite a word, sorry.
  • ➕ As a number, 20,634 = 2 × 3 × 19 × 181. Its digits add up to 15, a total 1,657 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101000010011010
  • 🏠 Its numerical neighbours: 20632 (Faulkner, MD, 28 mi away) and 20635 (Helen, MD, 8 mi away).
  • 🔄 Backwards, 20634 becomes 43602, which is not a ZIP code at all.
  • 👥 63 other ZIP codes are made of exactly the same digits (02346, 02364, 02634, 02643, 03246, 03264, …). The farthest-flung twin is 34260 in Manasota, FL, 822 miles away.
  • 🧭 Farther south than 57% of all ZIP codes, and farther east than 83%.
  • 🎯1,187 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 20634 and you would come out at 38.24°S, 103.50°E — 822 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 50m of daylight. Shortest: 9h 30m.
  • 📏 At 7.0 square miles of land, 20634 is bigger than 23% of ZIP codes — room for about 5.3 Central Parks.
🌙 The sky over 20634 today
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🌋 Shake report
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Source: USGS.

People and housing

Population7,088This ZIP7,088
Households2,694This ZIP2,694
Housing units3,026This ZIP3,026
Median age32.0This ZIP32.0Maryland39.4US 38.9
Median household income$139,375This ZIP$139,375Maryland$103,678US $80,734
Median home value$342,300This ZIP$342,300Maryland$419,900US $332,700
Median gross rent$1,814This ZIP$1,814Maryland$1,705US $1,413
Bachelor's degree or higher40.3%This ZIP40.3%
Mean commute23.6 minThis ZIP23.6 min
Population density1,013.9 / sq miThis ZIP1,013.9 / sq mi

Business and tax activity

Business establishments48This ZIP48
Employees393This ZIP393
Annual payroll$19,737,000This ZIP$19,737,000
Tax returns filed3,560This ZIP3,560
Total adjusted gross income$288,269,000This ZIP$288,269,000

Land area

Land area6.99 sq miThis ZIP6.99 sq mi
Water area0.07 sq miThis ZIP0.07 sq mi

Other place names in 20634

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

ZIP codes near 20634

ZIPCityDistance
20620 Callaway, MD 1.4 mi
20667 Park Hall, MD 3.3 mi
20653 Lexington Park, MD 3.8 mi
20619 California, MD 3.9 mi
20692 Valley Lee, MD 4.2 mi
20686 Saint Marys City, MD 5.2 mi
20670 Patuxent River, MD 5.7 mi
20630 Drayden, MD 5.9 mi
20690 Tall Timbers, MD 6.1 mi
20688 Solomons, MD 6.2 mi

Find every ZIP code within 10 miles of 20634 →

Questions about this ZIP code

Where is ZIP code 20634?

20634 is in Great Mills, Maryland, in St. Mary's County, part of the Lexington Park, MD metropolitan area. Its published point location is 38.2417, -76.4983.

What county is 20634 in?

20634 lies in St. Mary's County.

What time zone is 20634 in?

20634 uses America/New_York.

How many people live in 20634?

About 7,088 people live in ZIP code 20634, in 2,694 households, at 1,013.9 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 20634?

$139,375 a year, against $103,678 across Maryland.

What ZIP codes are near 20634?

The closest are 20620 (1.4 mi), 20667 (3.3 mi), 20653 (3.8 mi), 20619 (3.9 mi) and 20692 (4.2 mi).

Is 20634 a PO Box ZIP code?

20634 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “20634 ZIP Code — Great Mills, Maryland (St. Mary's County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/20634

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