# 47 (number)

 ← 46 47 48 →
Cardinalforty-seven
Ordinal47th
(forty-seventh)
Factorizationprime
Divisors1, 47
Roman numeralXLVII
Binary1011112
Ternary12023
Quaternary2334
Quinary1425
Senary1156
Octal578
Duodecimal3B12
Vigesimal2720
Base 361B36

 ← 46 47 48 →
Cardinalforty-seven
Ordinal47th
(forty-seventh)
Factorizationprime
Divisors1, 47
Roman numeralXLVII
Binary1011112
Ternary12023
Quaternary2334
Quinary1425
Senary1156
Octal578
Duodecimal3B12
Vigesimal2720
Base 361B36

47 (forty-seven) is the natural number following 46 and preceding 48.

## In mathematics

Forty-seven is the fifteenth prime number, a safe prime, the thirteenth supersingular prime, and the sixth Lucas prime. Forty-seven is a highly cototient number. It is an Eisenstein prime with no imaginary part and real part of the form $3n - 1$.

It is a Lucas number. Because its digits appear as successive terms earlier in the series of Lucas numbers: 2, 1, 3, 4, 7, 11, 18, 29, 47… ; it is also a Keith number.

Forty-seven is a strictly non-palindromic number.

Its representation in binary being 00101111, 47 is a prime Thabit number, and as such is related to the pair of amicable numbers {17296, 18416}.

Forty-seven is a Carol number.

## As an in-joke

Forty-seven has been the favorite number of Pomona College, California, USA, since 1964. A mathematical proof, written in 1964 by Professor Donald Bentley, supposedly demonstrates that all numbers are equal to 47.[4] However, Bentley offered it as a "joke proof" to further a popular student research project that listed real and imaginative "47 sightings". Bentley used the invalid proof to introduce his students to the concept of mathematical proofs.[5] The proof used limits to show that the sum of the two equal sides of an isosceles triangle is equal to the base side. Bentley chose forty-seven as the base side, but he could have used any number.

Joe Menosky graduated from Pomona College in 1979 and went on to become one of the story writers of Star Trek: The Next Generation. Menosky "infected" other Star Trek writers with an enthusiasm for the number 47.[6] As a result, 47, its reverse 74, its multiples, or combinations of 47 occur surreptitiously in almost every episode of the program and its spin-offs Star Trek: Deep Space Nine, Star Trek: Voyager and Star Trek: Enterprise.[4][7] Forty-seven might be mentioned in dialogue or appear on a computer screen, for example:

• In Star Trek Generations, Scotty manages to beam up only 47 El-Aurians before their ship is destroyed by the energy ribbon.
• In the TNG episode "Darmok", the computer of the Enterprise reports to have found 47 occurrences of the word "Darmok" in its database.
• In the DS9 episode "Whispers", the planet Parada 4 has seven moons.
• In the Voyager episode "Parallax", we learn that the Emergency Medical Holographic Channel is 47 and that the EMH has the experience of 47 individual medical officers.
• In the Voyager episode "Non Sequitur", Harry Kim lives in apartment 4-G, G being the seventh letter of the alphabet. The intentionality of this reference to 47 was confirmed by Brannon Braga, the writer of that episode.[8]
• In the Voyager episode "Before And After", the phase shift is 1.47
• In the 2009 film Star Trek, the Enterprise was built in Sector 47 of the Riverside Shipyards, and 47 Klingon ships are said to have been destroyed by Nero's ship, the Narada.

J. J. Abrams, who produced and directed the Star Trek film, carried a few references to the Star Trek franchise into contemporary episodes of his TV series Fringe, one of those references being the number 47. In the Season 1 episode "Bad Dreams", aired shortly before the release of Star Trek in theaters, Nick Lane's bulletin board features a large centrally-located sheet of paper with only the number 47 in huge typeface. It recurs again in the series, for example 47 minutes being the maximum amount of time for a time chamber in the series to last, and there being exactly 47 shapeshifters. J.J. Abrams continues to incorporate 47 into movies and series he produces and directs. There are many 47's in Fringe, Alias, and recently in Revolution, of which Abrams is a producer. In the Season 1 episode "Soul Train" of the series Revolution, the characters are involved with an old train engine where the engine number happens to be 47.[9]

## In popular culture

The number 47 recurs several times in the non-Oz novels of L. Frank Baum, published 1900-1918.

The 47 society is an outgrowth of the "movement" started at Pomona College.[4] They explore the belief that 47 occurs in nature more frequently than other numbers and share their personal sightings in consideration of 47 being "the quintessential random number".[10]

The tale of the Forty-seven Ronin is a historical Japanese story, based upon actual events that took place in year 1701 of the Western calendar. It is mentioned in John Frankenheimer's movie Ronin.

In the 1976 horror film The Omen, photographer Keith Jennings shows Ambassador Thorn that there are 47 crosses nailed to the door of Father Brennan's accommodation, in an attempt to keep Satanic forces from entering. This reference also occurs in David Seltzer's novelization of the film, although the same priest is named Father Tassone.[citation needed][importance?]

In the 2001 TV series Alias, the number 47 bears a specific significance concerning the Milo Rambaldi mythology. Among other things, page 47 of the Rambaldi manuscript contains the prophecy regarding the Chosen one and the Passenger. The number also often appears in different places through the series, for example in keycodes, safe-deposit boxes, hotel rooms or the number of victims in different attacks or accidents. It also appears as the same way in the 2008 TV series Fringe, which has the same creator as Alias..[citation needed][importance?]

The number 47 also appears in music. 47 is the number of miles of barbed wire walked by the singer of Bo Diddley's "Who Do You Love". In 1998, Japanese electronic musician Takako Minekawa released the album Cloudy Cloud Calculator, which featured a song about the number 47 entitled "Kangaroo Pocket Calculator". The song repeats, "47 is a magical number. 47 plus 2 equals 49. 47 times 2 equals 94. 49 and 94. 94 and 49. Relationship between 47 and 2… is magic" and eventually concludes, "Isn't it a coincidence?" Leslie Sarony published his song "Forty-Seven Ginger-Headed Sailors" in 1928.[11] Forty-seven is the usual number strings of a pedal harp. 47 is a song by Sunny Day Real Estate. Object 47 (named as the 47th release in the discography) is the name of an album release from Wire.

In video games, the main character of the Hitman series is known only by the name Agent 47. In Half-Life 2: Episode One, the protagonist, Gordon Freeman, begins the game with 47 points of health.

In National Treasure: Book of Secrets, the President asks Ben Gates to let him know what is on "page 47" of "the presidents book of secrets", which contains the national secrets of the U.S. presidents.

47 appears on the top of the police van in the Nicolas Cage film, Snake Eyes.

In David Lynch's movie Inland Empire, the film being shot is a remake of a doomed Polish feature named "47". In that film, the protagonist is trapped in "Room 47".

'47' is the fourth track on New Found Glory's 2009 album, Not Without a Fight. The song features the chorus: "I called you 46 times, and you answered on the 47th."

In J.J. Abrams' SUPER 8, one of the characters, "Charles" is trying to create and enter a film. Part of the film takes place in "warehouse 47"

47 is the total numbers of balloons that a player can collect in Rareware's Nintendo 64 game Diddy Kong Racing.

The Wild, Wild West is a song by The Escape Club from their similarly named debut album, Wild Wild West that begins with the verse "Forty seven dead beats living in the back street/north east west south all in the same house/sitting in a back room waiting for the big boom/I'm in a bedroom waiting for my baby".[12]

In the 2011 American spy film Mission: Impossible – Ghost Protocol produced by J.J. Abrams, train car #47 is the team's safehouse. At the end of the movie the team also meets up at Pier 47 in Seattle, WA. [13][14]

Millions of sinister black cubes switch on all over the world for 47 minutes in the Doctor Who episode “The Power of Three”. This seems to give alien invaders all the information they need to destroy the human race.

### Other appearances

Forty-seven is the number of Ray Garraty, the main character in The Long Walk by Stephen King. In the animated web series Afterworld, the worldwide EMP re-occurs every 47 minutes. The number 47 appears on every bottle produced by Full Sail Brewery of Hood River, Oregon. This was representative of the number of employees at one time, and CEO Irene Firmat was apparently amused that it was 47, supposedly the most common random number. The brewery now has more employees, but the number remains on the bottles.[15] In the Japanese manga Claymore, there are 47 Claymore warriors. The main character, Clare, is ranked 47th among these warriors.

## References

1. ^ The NGC / IC Project - Home of the Historically Corrected New General Catalogue (HCNGC) since 1993
2. ^ Internet Archive Wayback Machine
3. ^ NASA - Lunar Eclipses of Saros Series 1 to 175
4. ^ a b c "The Mystique of 47". Pomona College (via Internet Archive). Archived from the original on 2006-09-01. Retrieved 2010-05-16.
5. ^ "The Mystery of 47". Pomona College. Retrieved 2007-08-29.
6. ^ "Stardate 47". Pomona College (via Internet Archive). Retrieved 2010-05-17.
7. ^ "Starbase Pomona". Pomona College (via Internet Archive). Retrieved 2010-05-17.
8. ^ schlock.net: A letter from Brannon Braga
9. ^ Roco. "Revolution Observations: 1.05 Soul Train". Seriable.com. Retrieved 28 April 2013.
10. ^ The 47 Society
11. ^ Digital Collections - Music - Sarony, Leslie. The Church song "Destination" has a lyric, "Page forty-seven is unsigned, I need it by this evening." Forty-seven ginger-headed sailors [music]
12. ^ - Escape Club - Wild Wild West lyrics by alllyrics.com
13. ^ themarknight (22 December 2011). "Six easter eggs you may or may not have noticed in “Mission: Impossible – Ghost Protocol”". ViralNfection. WordPress.com. Archived from the original on 9 October 2012. Retrieved 9 January 2014.
14. ^ MovieMaps.org - Mission: Impossible - Ghost Protocol - Pier 47
15. ^ Oregon Business Magazine, October 2008