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ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — ZIP/17123

17123

ZIP 17123 is in Harrisburg, Pennsylvania, in Dauphin County; area codes 717 and 223; Eastern time. Harrisburg has 26 ZIP codes in all.

Type
No street area
Time zone
America/New_York
County
Dauphin
Coordinates
40.2675, -76.8837

The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

This ZIP code has no Census tabulation area of its own. Its point falls inside ZCTA 17102, whose figures describe that area — not this ZIP code.

☼ Live from 17123 — Harrisburg, PA

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Where 17123 is

This ZIP code has no Census tabulation area, so there is no boundary to draw — the marker is its published point location.

★ Weird and wonderful facts about 17123
  • 🔢 Type 17123 into a pocket calculator and turn it upside down: EZILI — not quite a word, sorry.
  • ➕ 17123 is a prime number. It cannot be divided by anything except 1 and itself. Its digits add up to 14, a total 1,416 other ZIP codes share.
  • 💾In binary, the way a computer stores it: 100001011100011
  • 🏠 Its numerical neighbours: 17122 (Harrisburg, PA, 1 mi away) and 17124 (Harrisburg, PA, 0 mi away).
  • 🔄 Backwards, 17123 becomes 32171, which is not a ZIP code at all.
  • 👥 26 other ZIP codes are made of exactly the same digits (11237, 11372, 11732, 12137, 12173, 13217, …). The farthest-flung twin is 73112 in Oklahoma City, OK, 1,172 miles away.
  • 🧭 Farther north than 59% of all ZIP codes, and farther east than 82%.
  • 🎯1,145 miles east of the geographic center of the Lower 48, near Lebanon, Kansas.
  • 🌏 Dig straight through the Earth from 17123 and you would come out at 40.27°S, 103.12°E — 913 miles from Perth, Australia, the nearest big city to that spot.
  • ☀Longest day of the year: 15h 03m of daylight. Shortest: 9h 18m.
🌙 The sky over 17123 today
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Source: USGS.

Land area

ZIP codes near 17123

ZIPCityDistance
17125 Harrisburg, PA 0.1 mi
17124 Harrisburg, PA 0.1 mi
17120 Harrisburg, PA 0.2 mi
17130 Harrisburg, PA 0.2 mi
17128 Harrisburg, PA 0.4 mi
17126 Harrisburg, PA 0.4 mi
17127 Harrisburg, PA 0.4 mi
17129 Harrisburg, PA 0.4 mi
17101 Harrisburg, PA 0.8 mi
17105 Harrisburg, PA 0.9 mi

Find every ZIP code within 10 miles of 17123 →

Questions about this ZIP code

Where is ZIP code 17123?

17123 is in Harrisburg, Pennsylvania, in Dauphin County, part of the Harrisburg-Carlisle, PA metropolitan area. Its published point location is 40.2675, -76.8837.

What county is 17123 in?

17123 lies in Dauphin County.

What area code is 17123?

Harrisburg uses area codes 717 and 223, from NANPA's telephone records.

What time zone is 17123 in?

17123 uses America/New_York.

What ZIP codes are near 17123?

The closest are 17125 (0.1 mi), 17124 (0.1 mi), 17120 (0.2 mi), 17130 (0.2 mi) and 17128 (0.4 mi).

Is 17123 a PO Box ZIP code?

Possibly. The Census map gives this ZIP code no delivery area of its own, which usually means it serves post office boxes, a single organization or a post office rather than streets of homes.

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Cite this page

zipcodes.pro. “17123 ZIP Code — Harrisburg, Pennsylvania (Dauphin County).” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/zip/17123

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