145 (number)

145 (one hundred [and] forty-five) is the natural number following 144 and preceding 146.

In mathematics

 * Although composite, 145 is a Fermat pseudoprime in sixteen bases with b < 145. In four of those bases, it is a strong pseudoprime: 1, 12, 17, and 144.
 * the Mertens function returns 0.
 * 145 is a pentagonal number and a centered square number.
 * $$145 = 12^2 + 1^2 = 8^2 + 9^2$$. 145 is the fourth number that is the sum of two different pairs of squares. Also, 145 is the result of 34 + 43, making it a Leyland number.
 * $$145 = 1! + 4! + 5!$$, making it a factorion. The only other numbers that have this property are 1, 2 and 40585.
 * $$145=5^2+5!=11^2+4!=12^2+1!$$, making 145 the smallest number that can be written as the sum of a square number and a factorial in 3 ways. The next number with this property is 46249.

In the military

 * USS Armada (AM-145) was a United States Navy Admirable-class minesweeper during World War II
 * USS Colbert (APA-145) was a United States Navy Haskell-class attack transport during World War II
 * USS General Harry Taylor (AP-145) was a United States Navy General G. O. Squier-class transport during World War II
 * USS Greer (DD-145) was a United States Navy Wickes-class destroyer during World War II
 * USS Huse (DE-145) was a United States Navy Edsall-class destroyer escort during World War II
 * USS Roanoke (CL-145) was a United States Navy Worcester-class cruiser following World War II

In sports

 * The Grand Union Canal Race is a 145-mile ultramarathon from Birmingham to London along the Grand Union Canal

In transportation

 * Eurocopter EC 145 is a twin-engine light utility helicopter
 * The Delahaye 145 Sports Car from 1938
 * The Alfa Romeo 145 car produced between 1994 and 2001
 * Volvo 145 Express station wagon
 * ERJ 145 regional jets produced by Embraer
 * Golden Gate Transit Bus Route 145
 * London Bus Route 145

In other fields
145 is also:
 * The year AD 145 or 145 BC
 * 145 AH is a year in the Islamic calendar that corresponds to 762 – 763 CE
 * 145 Adeona is a large main belt asteroid
 * Psalm 145
 * Sonnet 145
 * Apple Computer laptops, such as the PowerBook 145 and PowerBook 145B
 * Puff Daddy song “Picture it” includes the lyrics “in something foreign soarin’ 145”
 * Tsuu T'ina Nation 145 Indian reserve in Alberta, Canada
 * 145 mg medicine tablets, as with Tricor
 * "One Four Five" is a song by The Cat Empire