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Where 21920 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 21920 into a pocket calculator and turn it upside down: OZGIZ — not quite a word, sorry.
- ➕ As a number, 21,920 = 2 × 2 × 2 × 2 × 2 × 5 × 137. Its digits add up to 14, a total 1,416 other ZIP codes share.
- 💾In binary, the way a computer stores it:
101010110100000 - 🏠 Its numerical neighbours: 21919 (Earleville, MD, 17 mi away) and 21921 (Elkton, MD, 2 mi away).
- 🔄 Backwards, 21920 becomes 02912 — and that is a real ZIP code: Providence, RI, 276 miles away.
- 👥 36 other ZIP codes are made of exactly the same digits (01229, 01922, 02129, 02912, 02921, 09212, …). The farthest-flung twin is 09212 in APO AE, a military post office, 3,978 miles away.
- 🧭 Farther north than 53% of all ZIP codes, and farther east than 85%.
- 🎯1,205 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 21920 and you would come out at 39.66°S, 104.16°E — 843 miles from Perth, Australia, the nearest big city to that spot.
- ☀Longest day of the year: 14h 59m of daylight. Shortest: 9h 22m.
- 📏 At 0.989 square miles of land, 21920 is bigger than 8% of ZIP codes — about 479 football fields.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 1,413This ZIP1,413 |
|---|---|
| Households | 436This ZIP436 |
| Housing units | 436This ZIP436 |
| Median age | 36.7This ZIP36.7Maryland39.4US 38.9 |
| Median household income | $124,146This ZIP$124,146Maryland$103,678US $80,734 |
| Median home value | $356,000This ZIP$356,000Maryland$419,900US $332,700 |
| Median gross rent | $1,346This ZIP$1,346Maryland$1,705US $1,413 |
| Bachelor's degree or higher | 22.4%This ZIP22.4% |
| Mean commute | 37.5 minThis ZIP37.5 min |
| Population density | 1,428.7 / sq miThis ZIP1,428.7 / sq mi |
Land area
| Land area | 0.99 sq miThis ZIP0.99 sq mi |
|---|---|
| Water area | 0.01 sq miThis ZIP0.01 sq mi |
ZIP codes near 21920
| ZIP | City | Distance |
|---|---|---|
21916 | Childs, MD | 1.8 mi |
21921 | Elkton, MD | 2.2 mi |
21922 | Elkton, MD | 3.4 mi |
19351 | Lewisville, PA | 4.9 mi |
19717 | Newark, DE | 5.1 mi |
19716 | Newark, DE | 5.1 mi |
19360 | New London, PA | 5.7 mi |
19347 | Kemblesville, PA | 6.5 mi |
19702 | Newark, DE | 6.5 mi |
19711 | Newark, DE | 6.6 mi |
Find every ZIP code within 10 miles of 21920 →
Questions about this ZIP code
Where is ZIP code 21920?
21920 is in Elk Mills, Maryland, in Cecil County, part of the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD metropolitan area. Its published point location is 39.6562, -75.8410.
What county is 21920 in?
21920 lies in Cecil County.
What area code is 21920?
Elk Mills uses area codes 443, 410 and 667, from NANPA's telephone records.
What time zone is 21920 in?
21920 uses America/New_York.
How many people live in 21920?
About 1,413 people live in ZIP code 21920, in 436 households, at 1,428.7 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 21920?
$124,146 a year, against $103,678 across Maryland.
What ZIP codes are near 21920?
The closest are 21916 (1.8 mi), 21921 (2.2 mi), 21922 (3.4 mi), 19351 (4.9 mi) and 19717 (5.1 mi).
Is 21920 a PO Box ZIP code?
21920 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “21920 ZIP Code — Elk Mills, Maryland (Cecil County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21920
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/21920.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.