73

73 (seventy-three) is the natural number following 72 and preceding 74. In English, it is the smallest integer with twelve letters in its spelled out name.

In mathematics

Seventy-three is the 21st prime number. The previous is seventy-one, with which it comprises the 8th twin prime. It is also a permutable prime with thirty-seven. 73 is a star number.

Every positive integer is the sum of at most 73 sixth powers (see Waring's problem).

In base 5, the smallest prime with a composite sum of digits is 73.

73 is a repdigit in base 8 (111).

In science

• The atomic number of tantalum

In astronomy,

Messier object M73, a magnitude 9.0 apparent open cluster in the constellation Aquarius

The New General Catalogue object NGC 73, a barred spiral galaxy in the constellation Cetus

The Saros number of the solar eclipse series which began on 717 BC July 16 and ended on 582 September 3. The duration of Saros series 73 was 1298.1 years, and it contained 73 solar eclipses.

The number of seconds it took for the OV-099 shuttle to explode after launch.

In other fields

Seventy-three is also:

• The total number of books in the Holy Bible in the Catholic version if the Book of Lamentations is counted as a book separate from the Book of Jeremiah.
• The designation of USA Interstate 73, a freeway in North Carolina.
• The registry of the U.S. Navy's nuclear aircraft carrier USS George Washington (CVN-73), named after U.S. President George Washington.
• The year AD 73, 73 BC, or 1973.
• Amateur radio operators often use the number 73 as a abbreviation for "best regards", typically when ending a QSO (a conversation with another ham). [1] In Morse code, 73 is a palindrome (--··· ···--).
• 73 (also known as 73 Amateur Radio Today), was an amateur radio magazine published from 1960 to 2003.
• Each of the five seasons of the Discordian calendar has 73 days.
• No. 73 was name of a 1980s children's television programme in the United Kingdom. It ran from 1982-1988 and starred Sandi Toksvig
• The Blues Image song "Ride Captain Ride" (1970) begins with "73 men sailed out on the San Francisco Bay"
• Singer Johnny Mathis has had 73 charted albums on Billboard Top 200 Charts
• Pizza 73 is a Canadian pizza chain with 51 stores
• Game show Match Game '73 in 1973
• The Felony Squad aired on ABC from '66 - '69 for 73 episodes
• The TV show Hope & Faith aired on ABC, 2003 - 2006 for 73 episodes
• Fender Rhodes Stage 73 Piano
• Sonnet 73 by William Shakespeare
• PT-73, the PT boat on TV's McHale's Navy
• 73 is the current area of resistance to the downside of the iTraxx Europe Series 9 5y credit index. The number has taken on almost mythical status amongst the denizens of the financial community in London
• The number of the French department Savoie
• In Morse Code, 73 is used to express "love and kisses" (later reduced to the more formal "best regards").

In sports

• The car number of former NASCAR driver Johnny Beauchamp.
• The best-known car number of retired NASCAR driver Phil Barkdoll.
• In baseball, the single-season home run record set by Barry Bonds in 2001.
• In basketball, the number of games the Philadelphia 76ers lost in the 1972-73 season (9-73), the most losses in NBA history.
• University of Texas football player Jonathan Scott wore #73
• MLB: Kenny Rogers wore #73 with the New York Mets
• NFL: San Francisco 49ers Leo Nomellini wore #73
• NFL: New England Patriots John Hannah's retired #73
• NFL: New York Jets Joe Klecko's retired #73
• NFL: Indianapolis Colts Adam Meadows wore #73
• NFL: Cleveland Browns Alvin Smith wears #73
• NFL: Seattle Seahawks Wayne Hunter wears #73
• NFL: St. Louis Rams Jimmy Kennedy wears #73
• NFL: Dallas Cowboys Larry Allen wears #73
• NHL: Los Angeles Kings John Zeiler wears #73
• NHL: Boston Bruins Michael Ryder wears #73
• NFL: Green Bay Packers Daryn Colledge wears #73
• AFL: Geelong Cats defeated Collingwood Magpies by 73 points in the 2009 AFL Preliminary Final