89 (number)

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

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.