89 (eighty-nine) 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 88 and preceding 90.

In mathematics

89 is: * the 24th

prime number A prime number (or a prime) is a natural number greater than 1 that is not a 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 because the only way ...

, following 83 and preceding 97. * a Chen prime. * a Pythagorean prime. * the smallest Sophie Germain prime to start a Cunningham chain of the first kind of six terms, . * an Eisenstein prime with no imaginary part and real part of the form . * a

Fibonacci number In mathematics, the Fibonacci numbers, commonly denoted , form a integer sequence, sequence, the Fibonacci sequence, in which each number is the sum of the two preceding ones. The sequence commonly starts from 0 and 1, although some authors start ...

and thus a

Fibonacci prime A Fibonacci prime is a Fibonacci number that is prime, a type of integer sequence prime. The first Fibonacci primes are : : 2, 3, 5, 13, 89, 233, 1597, 28657, 514229, 433494437, 2971215073, .... Known Fibonacci primes It is not known wh ...

as well. The first few digits of its reciprocal coincide with the Fibonacci sequence due to the identity ::

\frac=\sum_^\infty=0.011235955\dots\ .

* a Markov number, appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers. ''M''₈₉ is the 10th

Mersenne prime In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form for some integer . They are named after Marin Mersenne, a French Minim friar, who studied them in the early 17 ...

. Although 89 is not a Lychrel number in base 10, it is unusual that it takes 24 iterations of the reverse and add process to reach a

palindrome A palindrome is a word, number, phrase, or other sequence of symbols that reads the same backwards as forwards, such as the words ''madam'' or ''racecar'', the date and time ''11/11/11 11:11,'' and the sentence: "A man, a plan, a canal – Panam ...

. Among the known non-Lychrel numbers in the first 10000 integers, no other number requires that many or more iterations. The palindrome reached is also unusually large. There are exactly 1000 prime numbers between 1 and 89².

In science

Eighty-nine is: * 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 every ...

of actinium.

In astronomy

Messier object The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only i ...

M89, a magnitude 11.5

elliptical galaxy An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Rea ...

in the constellation

Virgo Virgo may refer to: * Virgo (astrology), the sixth astrological sign of the zodiac * Virgo (constellation), a constellation * Virgo Cluster, a cluster of galaxies in the constellation Virgo * Virgo Stellar Stream, remains of a dwarf galaxy *Virgo ...

. *The New General Cataloguebr>object
NGC 89, a magnitude 13.5 peculiar

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''Phoenix and a member of Robert's Quartet.

In sports

* The Oklahoma Redhawks, an American minor league baseball team, were formerly known as the Oklahoma 89ers (1962–1997). The number alludes to the

Land Run of 1889 The Oklahoma Land Rush of 1889 was the first land run into the Unassigned Lands of former Indian Territory, which had earlier been assigned to the Creek and Seminole peoples. The area that was opened to settlement included all or part of Canadi ...

, when the

Unassigned Lands The Unassigned Lands in Oklahoma were in the center of the lands ceded to the United States by the Creek (Muskogee) and Seminole Indians following the Civil War and on which no other tribes had been settled. By 1883 it was bounded by the Cher ...

of Oklahoma were opened to

white White is the lightness, lightest color and is achromatic (having no hue). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully diffuse reflection, reflect and scattering, scatter all the ...

settlement. The team's home of

Oklahoma City Oklahoma City (), officially the City of Oklahoma City, and often shortened to OKC, is the capital and largest city of the U.S. state of Oklahoma. The county seat of Oklahoma County, it ranks 20th among United States cities in population, an ...

was founded during this event. * In Rugby, an "89" or eight-nine move is a phase following a scrum, in which the number 8 catches the ball and transfers it to number 9 (scrum half). * The

Elite 89 Award The Elite 90 Award or more formally The Elite 90 Academic Recognition Award Program, originally the Elite 88 Award and later the Elite 89 Award, is an award by the National Collegiate Athletic Association (NCAA) recognizing the student athlete ...

is presented by the U.S.

NCAA The National Collegiate Athletic Association (NCAA) is a nonprofit organization that regulates student athletics among about 1,100 schools in the United States, Canada, and Puerto Rico. It also organizes the athletic programs of colleges and ...

to the participant in each of the NCAA's 89 championship finals with the highest

grade point average Grading in education is the process of applying standardized measurements for varying levels of achievements in a course. Grades can be assigned as letters (usually A through F), as a range (for example, 1 to 6), as a percentage, or as a numbe ...

. * 89, a 2017 film about a football match, between Liverpool and Arsenal in 1989.

In other fields

Eighty-nine is also: *The designation of

Interstate 89 Interstate 89 (I-89) is an Interstate Highway in the New England region of the United States traveling from Bow, New Hampshire, to the Canadian border between Highgate Springs, Vermont, and Saint-Armand, Quebec. As with all odd-numb ...

, a freeway that runs from

New Hampshire New Hampshire is a state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec to the nor ...

Vermont Vermont () is a state in the northeast New England region of the United States. Vermont is bordered by the states of Massachusetts to the south, New Hampshire to the east, and New York to the west, and the Canadian province of Quebec to the ...

*The designation of

U.S. Route 89 U.S. Route 89 (US 89) is a north–south United States Numbered Highway with two sections, and one former section. The southern section runs for from Flagstaff, Arizona, to the southern entrance of Yellowstone National Park. The northern secti ...

, a north–south highway that runs from

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a U.S. state, state in the Southwestern United States. It is the list of U.S. states and territories by area, 6th largest and the list of U.S. states and territories by population, 14 ...

*The

ISBN The International Standard Book Number (ISBN) is a numeric commercial book identifier that is intended to be unique. Publishers purchase ISBNs from an affiliate of the International ISBN Agency. An ISBN is assigned to each separate edition an ...

Group Identifier for books published in

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republi ...

*" Pop Song 89" by R.E.M. * A model of the Texas Instruments calculator TI-89 * California

Proposition 89 Proposition 89 was a failed 2006 California ballot initiative that would have offered clean elections centered on campaign finance reform. Main points of Proposition 89 *Would levy a 0.2% tax on all businesses to help pay for clean money election ...

, a 2006 California ballot initiative on campaign finance reform * The title of a currently-unreleased song by

Bon Iver Bon Iver ( ) is an American indie folk band founded in 2006 by singer-songwriter Justin Vernon. Vernon released Bon Iver's debut album, ''For Emma, Forever Ago,'' independently in July 2007. The majority of the album was recorded while Vernon ...

* The greatest number of verses in a chapter of a book of the Bible other than the Book of Psalms—specifically

Numbers A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, 4, and so forth. Numbers can be represented in language with number words. More universally, individual numbers ca ...

chapter 7. * The number of units of each colour in the board game Blokus * The number of the French department

Yonne Yonne () is a department in the Bourgogne-Franche-Comté region in France. It is named after the river Yonne, which flows through it, in the country's north-central part. One of Bourgogne-Franche-Comté's eight constituent departments, it is l ...

* ''

Information Is Beautiful David McCandless (born 1971) is a British data-journalist, writer and information designer. Early life and education McCandless is an alumnus of Westfield College. Career McCandless is the founder of the visual blog ''Information Is Beautiful''. ...

'' cites eighty-nine as one of the words censored on the Chinese internet.

References