155 (one hundred [and] fifty-five) is the natural number following 154 and preceding 156. In mathematics 155 is: a composite number a semiprime. a deficient number, since 1+5+31=37<155. odious, since its binary expansion has a total of 5 ones in it. There are 155 primitive permutation groups of degree 81. If one adds up all the primes from the least through the greatest prime factors of 155, that is, 5 and 31, the result is 155. Only three other "small" semiprimes (10, 39, and 371) share this attribute. In the military was a United States Navy Admirable-class minesweeper during World War II was a United States Navy Wickes-class destroyer during World War II was a United States Navy General G. O. Squier-class transport during World War II was a United States Navy Buckley-class destroyer escort during World War II was a United States Navy during World War II was a United States Navy four-master wooden schooner during World War II 155mm artillery, a common caliber In sports The maximum possible score in a single break in snooker, with a free ball at the start of the break (147 is the highest possible without a free ball) In transportation Alfa Romeo 155, a compact executive car produced from 1992 to 1998 Seattle Bus Route 155 London Bus Route 155 The British Rail Class 155 is a diesel multiple unit British train Blériot 155 was a French airliner of the 1920s 155th Street, Manhattan, New York 155th Street New York City Subway stations: 155th Street (IND Concourse Line) 155th Street (IND Eighth Avenue Line) 155th Street (IRT Ninth Avenue Line) (former) In other fields 155 is also: The year AD 155 or 155 BC 155 is the number for the International Operator in the United Kingdom 155 AH is a year in the Islamic calendar that corresponds to 771 – 772 CE 155 Scylla is a main belt asteroid Europium-155 is a radioisotope or Europium and fission product with a half-life of 4.76 years 155, a 2007 song by the band +44 The dialing code for Obihiro, Japan The atomic number of an element temporarily called unquintquinttium 155 North Wacker is a 46-story skyscraper in Chicago Wolseley No. 155, Saskatchewan is a rural municipality in Canada See also List of highways numbered 155 United Nations Security Council Resolution 155 United States Supreme Court cases, Volume 155 Psalms 152–155 McHenry County, Illinois Community