Английская Википедия:169 (number)
169 (one hundred [and] sixty-nine) is the natural number following 168 and preceding 170.
In mathematics
169 is an odd number, a composite number, and a deficient number.
169 is a square number: 13 × 13 = 169, and if each number is reversed the equation is still true: 31 × 31 = 961. 144 shares this property: 12 × 12 = 144, 21 × 21 = 441.
169 is one of the few squares to also be a centered hexagonal number.[1] Like all odd squares, it is a centered octagonal number. 169 is an odd-indexed Pell number, thus it is also a Markov number, appearing in the solutions (2, 169, 985), (2, 29, 169), (29, 169, 14701), etc. 169 is the sum of seven consecutive primes: 13 + 17 + 19 + 23 + 29 + 31 + 37. 169 is a difference in consecutive cubes, equaling <math>8^3-7^3.</math>
In astronomy
- 169 Zelia is a bright main belt asteroid
- Gliese 169 is an orange, main sequence (K7 V) star in the constellation Taurus
- QSO B0307+169 is a quasar in the constellation Aries
- Sayh al Uhaymir 169 is a 206g lunar meteorite found in Sultanate of Oman
In the military
- Шаблон:USNS was a United States Navy technical research ship during the 1960s
- Шаблон:USS was a United States Navy Шаблон:Sclass during World War II
- Шаблон:USS was a United States Navy Шаблон:Sclass during World War II
- Шаблон:USS was a United States Navy Шаблон:Sclass following World War I
- Шаблон:USS was a United States Navy Шаблон:Sclass during World War II
- Шаблон:USS was a United States Navy submarine during World War II
- 169th Battalion, CEF unit in the Canadian Expeditionary Force during the World War I
- 169th Fires Brigade the US Army National Guard artillery brigade, a part of the Colorado Army National Guard
- The United States Air Force's 169th Fighter Wing fighter unit at McEntire Joint National Guard Station, South Carolina
- 169 or 169th Squadrons
- 169th Airlift Squadron, a unit of the U.S. Air Force
- Marine Light Attack Helicopter Squadron 169, United States Marine Corps Light Attack Helicopter Squadron
- No. 169 Squadron RAF, a unit of the United Kingdom Royal Air Force
In transportation
- Metro Transit Route 169 in Seattle[2]
- 169th Street station on the IND Queens Boulevard Line of the New York City Subway served by the Шаблон:NYCS and Шаблон:NYCS trains
- 169th Street was a station on the demolished IRT Third Avenue Line of the New York City Subway
In TV and radio
- The IEC 169-2 connector TV aerial plug
In other fields
169 is also:
- The year AD 169 or 169 BC
- The atomic number of an element temporarily called Unhexennium[3]
- 169 is the number of nonequivalent starting hands in the card game Texas hold 'em
- 169 is known in the computing world as the first number of an automatic IPv4 address assigned by TCP/IP when no external networking device is contactable
- Minuscule 169 is a Greek minuscule manuscript of the New Testament, on parchment
See also
- List of highways numbered 169
- United States Supreme Court cases, Volume 169
- United Nations Security Council Resolution 169
- St. Joseph Community Consolidated School District 169
References
External links
- Number Facts and Trivia: 169
- The Positive Integer 169
- Prime curiosities: 169
- The Number 169
- Number Gossip 169
