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zipcodes.pro — ZIP/21784

21784

ZIP 21784 is Sykesville, Maryland, mostly in Carroll County; area codes 443, 410 and 667; Eastern time.

Type
Standard
Time zone
America/New_York
County
Carroll +1 more
Population
39,258
Coordinates
39.4011, -76.9737
☼ Live from 21784 — Sykesville, MD

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Where 21784 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 21784
  • 🔢 Type 21784 into a pocket calculator and turn it upside down: hBLIZ — not quite a word, sorry.
  • ➕ As a number, 21,784 = 2 × 2 × 2 × 7 × 389. Its digits add up to 22, a total 2,607 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 101010100011000
  • 🏠 Its numerical neighbours: 21783 (Smithsburg, MD, 35 mi away) and 21787 (Taneytown, MD, 22 mi away).
  • 🔄 Backwards, 21784 becomes 48712, which is not a ZIP code at all.
  • 👥 49 other ZIP codes are made of exactly the same digits (12487, 12748, 12784, 12847, 12874, 14728, …). The farthest-flung twin is 84721 in Cedar City, UT, 1,943 miles away.
  • 🧭 Farther north than 52% of all ZIP codes, and farther east than 82%.
  • 🎯1,148 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 21784 and you would come out at 39.40°S, 103.03°E — 884 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 14h 57m of daylight. Shortest: 9h 23m.
  • 📏 At 56.1 square miles of land, 21784 is bigger than 63% of ZIP codes — room for about 43 Central Parks.
🌙 The sky over 21784 today
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🌋 Shake report
  • Checking the USGS…

Source: USGS.

People and housing

Population39,258This ZIP39,258
Households13,416This ZIP13,416
Housing units13,797This ZIP13,797
Median age38.9This ZIP38.9Maryland39.4US 38.9
Median household income$139,395This ZIP$139,395Maryland$103,678US $80,734
Median home value$491,800This ZIP$491,800Maryland$419,900US $332,700
Median gross rent$1,739This ZIP$1,739Maryland$1,705US $1,413
Bachelor's degree or higher53.0%This ZIP53.0%
Mean commute33.3 minThis ZIP33.3 min
Population density699.4 / sq miThis ZIP699.4 / sq mi

Business and tax activity

Business establishments975This ZIP975
Employees12,994This ZIP12,994
Annual payroll$662,024,000This ZIP$662,024,000
Tax returns filed19,810This ZIP19,810
Total adjusted gross income$2,374,944,000This ZIP$2,374,944,000

Land area

Land area56.13 sq miThis ZIP56.13 sq mi
Water area2.03 sq miThis ZIP2.03 sq mi

Counties 21784 spans

A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.

CountyShare of this ZIP
Carroll County 82.0%
Howard County 18.0%

Other place names in 21784

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

ZIP codes near 21784

ZIPCityDistance
21104 Marriottsville, MD 5.0 mi
21723 Cooksville, MD 5.2 mi
21765 Lisbon, MD 6.8 mi
21797 Woodbine, MD 7.0 mi
21794 West Friendship, MD 7.1 mi
21048 Finksburg, MD 7.3 mi
21136 Reisterstown, MD 7.4 mi
21163 Woodstock, MD 8.0 mi
21133 Randallstown, MD 8.8 mi
21738 Glenwood, MD 8.8 mi

Find every ZIP code within 10 miles of 21784 →

Questions about this ZIP code

Where is ZIP code 21784?

21784 is in Sykesville, Maryland, in Carroll County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.4011, -76.9737.

What county is 21784 in?

21784 spans 2 counties: Carroll County and Howard County. Most of it falls in Carroll County, measured by overlapping land area — the county holding the most land in a ZIP code is not always the one holding the most residents.

What area code is 21784?

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

What time zone is 21784 in?

21784 uses America/New_York.

How many people live in 21784?

About 39,258 people live in ZIP code 21784, in 13,416 households, at 699.4 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 21784?

$139,395 a year, against $103,678 across Maryland.

What ZIP codes are near 21784?

The closest are 21104 (5 mi), 21723 (5.2 mi), 21765 (6.8 mi), 21797 (7 mi) and 21794 (7.1 mi).

Is 21784 a PO Box ZIP code?

21784 is a standard ZIP code. A normal ZIP code with street delivery.

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Cite this page

zipcodes.pro. “21784 ZIP Code — Sykesville, Maryland (Carroll County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21784

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