161 (number)

In mathematics

• 161 is the sum of five consecutive prime numbers: 23, 29, 31, 37, and 41
• 161 is a hexagonal pyramidal number.
• 161 is a semiprime. Since its prime factors 7 and 23 are both Gaussian primes, 161 is a Blum integer.
• 161 is a palindromic number

  In the military

• was a U.S. Navy Type T2 tanker during World War II
• was a U.S. Navy during World War II
• was a U.S. Navy Trefoil-class concrete barge during World War II
• was a U.S. Navy during World War II
• was a U.S. Navy during World War II
• was a U.S. Navy during World War II
• was a U.S. Navy wooden yacht during World War I
• was a U.S. Navy during World War II
• was a U.S. Navy Achomawi-class fleet ocean tug following World War II
• was a U.S. Navy fourth-group S-class submarine between 1920 and 1931
• is a fictional U.S. Navy diesel engine submarine featured in the 1996 film Down Periscope
• The 161st Intelligence Squadron unit of the Kansas Air National Guard. Its parent unit is the 184th Intelligence Wing

  In music

• The Bose 161 Speaker System
• The Kay K-161 ThinTwin guitar

  In transportation

• MTA Maryland commuter bus 161
• Seattle
• London Bus route 161

  In other fields

• The year AD 161 or 161 BC
• 161 AH is a year in the Islamic calendar that corresponds to 777 - 778 CE
• The atomic number of an element temporarily called
• 161 Athor is an M-type Main belt asteroid
• E.161 is an ITU-T assigns letters to the 12-key telephone keypad
• Fiorina Fury 161 is a foundry facility and penal colony from the film Alien 3
• 161 is used by Anti Fascist Action as a code for AFA, sometimes used in 161>88