Weather right now
Asking the National Weather Service…
Where 21737 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 21737 into a pocket calculator and turn it upside down: LELIZ — not quite a word, sorry.
- ➕ 21737 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 20, a total 2,586 other ZIP codes share.
- 💾In binary, the way a computer stores it:
101010011101001 - 🏠 Its numerical neighbours: 21734 (Funkstown, MD, 44 mi away) and 21738 (Glenwood, MD, 2 mi away).
- 🔄 Backwards, 21737 becomes 73712, which is not a ZIP code at all.
- 👥 28 other ZIP codes are made of exactly the same digits (12737, 17237, 17327, 17372, 17723, 21773, …). The farthest-flung twin is 77213 in Houston, TX, 1,229 miles away.
- 🧭 Farther north than 51% of all ZIP codes, and farther east than 81%.
- 🎯1,146 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 21737 and you would come out at 39.25°S, 102.97°E — 881 miles from Perth, Australia, the nearest big city to that spot.
- ☀Longest day of the year: 14h 56m of daylight. Shortest: 9h 24m.
- 📏 At 5.1 square miles of land, 21737 is bigger than 19% of ZIP codes — room for about 3.9 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 2,474This ZIP2,474 |
|---|---|
| Households | 739This ZIP739 |
| Housing units | 739This ZIP739 |
| Median age | 38.8This ZIP38.8Maryland39.4US 38.9 |
| Median household income | $250,000+This ZIP$250,000+Maryland$103,678US $80,734 |
| Median home value | $996,400This ZIP$996,400Maryland$419,900US $332,700 |
| Bachelor's degree or higher | 75.8%This ZIP75.8% |
| Mean commute | 33.1 minThis ZIP33.1 min |
| Population density | 483.0 / sq miThis ZIP483.0 / sq mi |
Business and tax activity
| Business establishments | 83This ZIP83 |
|---|---|
| Employees | 678This ZIP678 |
| Annual payroll | $39,442,000This ZIP$39,442,000 |
| Tax returns filed | 1,010This ZIP1,010 |
| Total adjusted gross income | $229,974,000This ZIP$229,974,000 |
Land area
| Land area | 5.12 sq miThis ZIP5.12 sq mi |
|---|---|
| Water area | 0.05 sq miThis ZIP0.05 sq mi |
ZIP codes near 21737
| ZIP | City | Distance |
|---|---|---|
21036 | Dayton, MD | 1.4 mi |
21738 | Glenwood, MD | 2.2 mi |
20833 | Brookeville, MD | 3.2 mi |
21029 | Clarksville, MD | 4.3 mi |
21041 | Ellicott City, MD | 4.6 mi |
21150 | Simpsonville, MD | 4.6 mi |
20862 | Brinklow, MD | 4.7 mi |
21794 | West Friendship, MD | 4.8 mi |
21723 | Cooksville, MD | 5.7 mi |
20777 | Highland, MD | 5.9 mi |
Find every ZIP code within 10 miles of 21737 →
Questions about this ZIP code
Where is ZIP code 21737?
21737 is in Glenelg, Maryland, in Howard County, part of the Baltimore-Columbia-Towson, MD metropolitan area. Its published point location is 39.2483, -77.0271.
What county is 21737 in?
21737 lies in Howard County.
What area code is 21737?
Glenelg uses area codes 443, 667 and 410, from NANPA's telephone records.
What time zone is 21737 in?
21737 uses America/New_York.
How many people live in 21737?
About 2,474 people live in ZIP code 21737, in 739 households, at 483.0 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 21737?
$250,000+ a year, against $103,678 across Maryland.
What ZIP codes are near 21737?
The closest are 21036 (1.4 mi), 21738 (2.2 mi), 20833 (3.2 mi), 21029 (4.3 mi) and 21041 (4.6 mi).
Is 21737 a PO Box ZIP code?
21737 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “21737 ZIP Code — Glenelg, Maryland (Howard County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/21737
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/21737.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.