Английская Википедия:89 (number)

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Шаблон:Infobox number 89 (eighty-nine) is the natural number following 88 and preceding 90.

In mathematics

89 is:

<math>\frac{1}{89}=\sum_{n=1}^\infty{F(n)\times 10^{-(n+1)}}=0.011235955\dots\ .</math>
  • a Markov number, appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers.

M89 is the 10th Mersenne prime.

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. 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: 8813200023188.[4]

There are exactly 1000 prime numbers between 1 and 892=7921. [5]

In science

Eighty-nine is:

In astronomy

In sports

In other fields

Файл:TI-89.jpg
TI-89
Файл:Diaethria clymena or Cramer's Eighty-eight.jpg underside Tr.jpg
Diaethria clymena eyespots

Eighty-nine is also:

See also

References

Шаблон:Integers