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Where 00631 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 00631 into a pocket calculator and turn it upside down: IEgOO — not quite a word, sorry.
- ➕ 00631 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 10, a total 513 other ZIP codes share.
- 💾In binary, the way a computer stores it:
1001110111 - 🏠 Its numerical neighbours: 00627 (Camuy, PR, 16 mi away) and 00636 (Rosario, PR, 16 mi away).
- 🔄 Backwards, 00631 becomes 13600, which is not a ZIP code at all.
- 👥 32 other ZIP codes are made of exactly the same digits (00613, 01036, 01063, 01360, 01603, 03061, …). The farthest-flung twin is 61030 in Forreston, IL, 2,127 miles away.
- 🧭 Farther south than 99% of all ZIP codes, and farther east than 98%.
- 🎯2,410 miles southeast of the geographic center of the Lower 48, near Lebanon, Kansas.
- 🌏 Dig straight through the Earth from 00631 and you would come out at 18.18°S, 113.17°E — 673 miles from Denpasar, Indonesia, the nearest big city to that spot.
- ☀Longest day of the year: 13h 13m of daylight. Shortest: 11h 02m.
- 📏 At 3.1 square miles of land, 00631 is bigger than 15% of ZIP codes — room for about 2.4 Central Parks.
- Working out the sun…
- Checking the USGS…
Source: USGS.
People and housing
| Population | 1,321This ZIP1,321 |
|---|---|
| Households | 450This ZIP450 |
| Housing units | 604This ZIP604 |
| Median age | 48.0This ZIP48.0Puerto Rico44.8US 38.9 |
| Median household income | $19,278This ZIP$19,278Puerto Rico$26,297US $80,734 |
| Median home value | $99,800This ZIP$99,800Puerto Rico$131,500US $332,700 |
| Median gross rent | $336This ZIP$336Puerto Rico$578US $1,413 |
| Bachelor's degree or higher | 32.1%This ZIP32.1% |
| Mean commute | 30.9 minThis ZIP30.9 min |
| Population density | 422.6 / sq miThis ZIP422.6 / sq mi |
Land area
| Land area | 3.13 sq miThis ZIP3.13 sq mi |
|---|---|
| Water area | 0.27 sq miThis ZIP0.27 sq mi |
Counties 00631 spans
A ZIP code is a mail route and ignores county lines. Shares are by overlapping land area.
| County | Share of this ZIP |
|---|---|
| Adjuntas Municipio | 50.5% |
| Lares Municipio | 49.5% |
ZIP codes near 00631
| ZIP | City | Distance |
|---|---|---|
00601 | Adjuntas, PR | 5.3 mi |
00611 | Angeles, PR | 6.5 mi |
00669 | Lares, PR | 6.9 mi |
00606 | Maricao, PR | 6.9 mi |
00698 | Yauco, PR | 7.8 mi |
00641 | Utuado, PR | 10.3 mi |
00656 | Guayanilla, PR | 10.3 mi |
00637 | Sabana Grande, PR | 10.5 mi |
00670 | Las Marias, PR | 10.8 mi |
00624 | Penuelas, PR | 11.6 mi |
Find every ZIP code within 10 miles of 00631 →
Questions about this ZIP code
Where is ZIP code 00631?
00631 is in Castaner, Puerto Rico, in Adjuntas Municipio. Its published point location is 18.1843, -66.8308.
What county is 00631 in?
00631 spans 2 counties: Adjuntas Municipio and Lares Municipio. Most of it falls in Adjuntas Municipio, 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 00631?
Castaner uses area codes 939 and 787, from NANPA's telephone records.
What time zone is 00631 in?
00631 uses America/Puerto_Rico.
How many people live in 00631?
About 1,321 people live in ZIP code 00631, in 450 households, at 422.6 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 00631?
$19,278 a year, against $26,297 across Puerto Rico.
What ZIP codes are near 00631?
The closest are 00601 (5.3 mi), 00611 (6.5 mi), 00669 (6.9 mi), 00606 (6.9 mi) and 00698 (7.8 mi).
Is 00631 a PO Box ZIP code?
00631 is a standard ZIP code. A normal ZIP code with street delivery.
Download or cite
Cite this page
zipcodes.pro. “00631 ZIP Code — Castaner, Puerto Rico (Adjuntas Municipio).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/00631
Machine-readable version of these facts:
curl https://zipcodes.pro/zip/00631.jsonUnderlying data is public domain or openly licensed — sources, vintages and licences.