71 (seventy-one) is the
natural number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country").
Numbers used for counting are called '' cardinal ...
following
70 and preceding
72.
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In mathematics
71 is:
*the 20th
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime ...
. The next is
73, with which it composes a
twin prime.
*a
permutable prime and
emirp with
17.
*is the largest number which occurs as a prime factor of an order of a
sporadic simple group.
*the sum of three consecutive primes:
19,
23 and
29.
*a
centered heptagonal number.
*an
Eisenstein prime with no imaginary part and real part of the form 3''n'' – 1.
*a
Pillai prime In number theory, a Pillai prime is a prime number ''p'' for which there is an integer ''n'' > 0 such that the factorial of ''n'' is one less than a multiple of the prime, but the prime is not one more than a multiple of ''n''. To put it algebraical ...
, since 9! + 1 is divisible by 71 but 71 is not one more than a multiple of 9.
*the largest (15th)
supersingular prime, which is also a
Chen prime.
*part of the last known pair (71, 7) of
Brown number
Brocard's problem is a problem in mathematics that asks to find integer values of n and m for which
n!+1 = m^2,
where n! is the factorial. It was posed by Henri Brocard in a pair of articles in 1876 and 1885, and independently in 1913 by Sriniv ...
s, since 71
2 = 7! + 1.
*the twenty-third term of the
Euclid–Mullin sequence The Euclid–Mullin sequence is an infinite sequence of distinct prime numbers, in which each element is the least prime factor of one plus the product of all earlier elements. They are named after the ancient Greek mathematician Euclid, because ...
, as it is the least prime factor of one more than the product of the first twenty-two terms.
*the smallest positive integer ''d'' such that the imaginary
quadratic field Q() has
class number = 7.
*the
algebraic
Algebraic may refer to any subject related to algebra in mathematics and related branches like algebraic number theory and algebraic topology. The word algebra itself has several meanings.
Algebraic may also refer to:
* Algebraic data type, a data ...
degree of
Conway's constant, a remarkable number arising in the study of
look-and-say sequences.
*the sum of primes less than 71 (2 through 67) is 568, which is divisible by 71.
*71 is the only number between 1 and 100 that is one less or one more than divisible by all numbers from 2 to 10 (70: 2, 5, 7, 10) (72: 2, 3, 4, 6, 8, 9).
*71 is an index of a prime Lucas number.
In science
*The
atomic number
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of ever ...
of
lutetium, a lanthanide
In astronomy
*
Messier object M71, a
magnitude 8.5
globular cluster in the
constellation Sagitta
* The
New General Cataloguebr>
objectNGC 71
NGC 71 is an elliptical galaxy located in the constellation Andromeda. It is in the NGC 68 group. The galaxy was discovered by R. J. Mitchell in 1855, and observed in 1865 by Heinrich d'Arrest, who described it as "extremely faint, very small, ...
, a magnitude 13.2
peculiar spiral galaxy in the constellation
Andromeda
In other fields
Seventy-one is also:
* The number of different characters that can be used with a standard English
keyboard
Keyboard may refer to:
Text input
* Keyboard, part of a typewriter
* Computer keyboard
** Keyboard layout, the software control of computer keyboards and their mapping
** Keyboard technology, computer keyboard hardware and firmware
Music
* Mu ...
, excluding uppercase letters
* The registry of the U.S. Navy's nuclear aircraft carrier
USS ''Theodore Roosevelt'' (CVN-71), named after U.S. President
Theodore Roosevelt
* The number of the French department
Saône-et-Loire
* The year
AD 71,
71 BC
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Year 71 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Lentulus and Orestes (or, less frequently, year 683 ''Ab urbe condita''). The denomination 71 BC for this year has been u ...
, or
1971
* In the Mexican television sitcom, ''
El Chavo del Ocho
''El Chavo'' (English: ''The Kid''); — also known as ''El Chavo del Ocho'' (English: ''The Kid from number Eight'') during its earliest episodes —, is a Mexican television sitcom created by Roberto Gómez Bolaños, produced by Televisa. ...
'', Doña Clotilde lives in the apartment number 71, being therefore known as "La Bruja del 71" (
Spanish: "The Witch from Number 71")
* Lockheed
SR-71 Blackbird long-range, Mach 3 strategic reconnaissance aircraft
* ''
71 Fragments of a Chronology of Chance'', a film by
Michael Haneke
Michael Haneke (; born 23 March 1942) is an Austrian film director and screenwriter. His work often examines social issues and depicts the feelings of estrangement experienced by individuals in modern society. Haneke has made films in French, G ...
* ''
71: Into the Fire'', South Korean film about the
Korean War
{{Infobox military conflict
, conflict = Korean War
, partof = the Cold War and the Korean conflict
, image = Korean War Montage 2.png
, image_size = 300px
, caption = Clockwise from top:{ ...
* The form number for the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
Office of Personnel Management for requesting a leave of absence
* The
Irish Rail
Irish may refer to:
Common meanings
* Someone or something of, from, or related to:
** Ireland, an island situated off the north-western coast of continental Europe
***Éire, Irish language name for the isle
** Northern Ireland, a constituent unit ...
071 Class diesel locomotive
* In the
Jason Bourne novels by American author
Robert Ludlum the department within the
CIA
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, ...
which made Bourne and the other super agents is called
Treadstone Seventy-One.
*
SR-71
The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation. It was operated by the United States Air Force ...
, an
American
American(s) may refer to:
* American, something of, from, or related to the United States of America, commonly known as the "United States" or "America"
** Americans, citizens and nationals of the United States of America
** American ancestry, pe ...
alternative rock
Alternative rock, or alt-rock, is a category of rock music that emerged from the independent music underground of the 1970s and became widely popular in the 1990s. "Alternative" refers to the genre's distinction from mainstream or commercial ...
band
* The number of the laps of the
Austrian Grand Prix,
Mexican Grand Prix, and
Brazilian Grand Prix
The Brazilian Grand Prix ( pt, Grande Prêmio do Brasil), currently held under the name São Paulo Grand Prix ( pt, Grande Prêmio de São Paulo), is a Formula One championship race which is currently held at the Autódromo José Carlos Pace ...
References
{{Integers, zero
Integers