169 (number)

← 168 169 170 →
← 160 161 162 163 164 165 166 167 168 169 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	one hundred sixty-nine
Ordinal	169th (one hundred and sixty-ninth)
Factorization	13^2
Divisors	1, 13, 169
Roman numeral	CLXIX
Binary	101010012
Ternary	200213
Quaternary	22214
Quinary	11345
Senary	4416
Octal	2518
Duodecimal	12112
Hexadecimal	A916
Vigesimal	8920
Base 36	4P36

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 x 13 = 169, and if each number is reversed the equation is still true: 31 x 31 = 961. 144 shares this property: 12 x 12 = 144, 21 x 21 = 441.

169 is one of the few squares to also be a centered hexagonal number. 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 $8^3-7^3.$

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 geography

• Pittville No. 169, Saskatchewan is a rural municipality in Saskatchewan, Canada

In the military

• USNS Private Jose F. Valdez (T-AG-169) was a United States Navy technical research ship during the 1960s
• USS Chatham (AK-169) was a United States Navy Alamosa-class cargo ship during World War II
• USS Gallatin (APA-169) was a United States Navy Haskell-class attack transport during World War II
• USS Foote (DD-169) was a United States Navy Wickes-class destroyer following World War I
• USS Atherton (DE-169) was a United States Navy Cannon-class destroyer escort during World War II
• USS Dolphin (SS-169) 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
• 169th Street station on the IND Queens Boulevard Line of the New York City Subway served by the E and F 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
• 169 is the number of nonequivalent starting hands in the card game Texas hold 'em
• 169 is on the scoreboard on the video game Guitar Hero along with the number 666
• 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

External links

• Number Facts and Trivia: 169
• The Positive Integer 169
• Prime curiosities: 169
• The Number 169
• VirtueScience: 169
• Number Gossip 169