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Where 21555 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.
- 🔢 Type 21555 into a pocket calculator and turn it upside down: SSSIZ — not quite a word, sorry.
- ➕ As a number, 21,555 = 3 × 3 × 5 × 479. Its digits add up to 18, a total 2,332 other ZIP codes share.
- 💾In binary, the way a computer stores it:
101010000110011 - 🏠 Its numerical neighbours: 21550 (Oakland, MD, 46 mi away) and 21556 (Pinto, MD, 15 mi away).
- 🔄 Backwards, 21555 becomes 55512, which is not a ZIP code at all.
- 👥 9 other ZIP codes are made of exactly the same digits (12555, 15255, 15552, 25515, 51525, 51552, …). The farthest-flung twin is 51525 in Carson, IA, 893 miles away.
- 🧭 Farther north than 53% of all ZIP codes, and farther east than 78%.
- 🎯1,062 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 21555 and you would come out at 39.58°S, 101.44°E — 963 miles from Perth, Australia, the nearest big city to that spot.
- ☀Longest day of the year: 14h 58m of daylight. Shortest: 9h 22m.
- 📏 At 98.3 square miles of land, 21555 is bigger than 77% of ZIP codes — room for about 75 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 1,470This ZIP1,470 |
|---|---|
| Households | 591This ZIP591 |
| Housing units | 831This ZIP831 |
| Median age | 42.6This ZIP42.6Maryland39.4US 38.9 |
| Median household income | $53,266This ZIP$53,266Maryland$103,678US $80,734 |
| Median home value | $197,700This ZIP$197,700Maryland$419,900US $332,700 |
| Median gross rent | $790This ZIP$790Maryland$1,705US $1,413 |
| Bachelor's degree or higher | 11.9%This ZIP11.9% |
| Mean commute | 26.6 minThis ZIP26.6 min |
| Population density | 15.0 / sq miThis ZIP15.0 / sq mi |
Business and tax activity
| Business establishments | 11This ZIP11 |
|---|---|
| Employees | 52This ZIP52 |
| Annual payroll | $995,000This ZIP$995,000 |
| Tax returns filed | 700This ZIP700 |
| Total adjusted gross income | $41,169,000This ZIP$41,169,000 |
Land area
| Land area | 98.29 sq miThis ZIP98.29 sq mi |
|---|---|
| Water area | 1.98 sq miThis ZIP1.98 sq mi |
Other place names in 21555
Census places whose land this ZIP code overlaps. The Postal Service may accept other city names in an address, too.
ZIP codes near 21555
| ZIP | City | Distance |
|---|---|---|
25431 | Levels, WV | 6.3 mi |
26722 | Green Spring, WV | 6.5 mi |
21504 | Cumberland, MD | 6.8 mi |
21530 | Flintstone, MD | 7.3 mi |
21560 | Spring Gap, MD | 7.7 mi |
26763 | Springfield, WV | 10.1 mi |
25444 | Slanesville, WV | 10.3 mi |
25437 | Points, WV | 10.5 mi |
26767 | Wiley Ford, WV | 10.7 mi |
25434 | Paw Paw, WV | 10.8 mi |
Find every ZIP code within 10 miles of 21555 →
Questions about this ZIP code
Where is ZIP code 21555?
21555 is in Oldtown, Maryland, in Allegany County, part of the Cumberland, MD-WV micropolitan area. Its published point location is 39.5751, -78.5626.
What county is 21555 in?
21555 lies in Allegany County.
What area code is 21555?
Oldtown uses area codes 240, 301 and 227, from NANPA's telephone records.
What time zone is 21555 in?
21555 uses America/New_York.
How many people live in 21555?
About 1,470 people live in ZIP code 21555, in 591 households, at 15.0 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 21555?
$53,266 a year, against $103,678 across Maryland.
What ZIP codes are near 21555?
The closest are 25431 (6.3 mi), 26722 (6.5 mi), 21504 (6.8 mi), 21530 (7.3 mi) and 21560 (7.7 mi).
Is 21555 a PO Box ZIP code?
21555 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “21555 ZIP Code — Oldtown, Maryland (Allegany County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21555
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/21555.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.