155 (number)

← 154 155 156 →
← 150 151 152 153 154 155 156 157 158 159 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	one hundred fifty-five
Ordinal	155th (one hundred fifty-fifth)
Factorization	5 × 31
Divisors	1, 5, 31, 155
Greek numeral	ΡろーΝにゅーΕいぷしろん´
Roman numeral	CLV
Binary	100110112
Ternary	122023
Senary	4156
Octal	2338
Duodecimal	10B12
Hexadecimal	9B16

155 (one hundred [and] fifty-five) is the natural number following 154 and preceding 156. It is a composite number and a semiprime.

If you add up all the primes from the least through the greatest prime factors of 155, that is, 5 and 31, the result is 155. (sequence A055233 in the OEIS) Only three other small semiprimes (10, 39, and 371) share this attribute.

There are 155 primitive permutations of degree 81. OEIS: A000019

In the military

• USS Capable (AM-155) was a United States Navy Admirable minesweeper ship during World War II
• USS Cole (DD-155) was a United States Navy Wickes-class destroyer during World War II
• USS General A. W. Brewster (AP-155) was a United States Navy General G. O. Squier transport ship during World War II
• USS Hopping (DE-155) was a United States Navy Buckley destroyer escort ship during World War II
• USS Lycoming (APA-155) was a United States Navy Haskell-class attack transport during World War II
• USS Mustang (IX-155) was a United States Navy four-master wooden schooner during World War II

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 1992–1998
• 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 under construction 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 High School District 155