89809 has 2 divisors, whose sum is σ = 89810. Its totient is φ = 89808.

The previous prime is 89797. The next prime is 89819. The reversal of 89809 is 90898.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88209 + 1600 = 297^2 + 40^2 .

It is a cyclic number.

It is not a de Polignac number, because 89809 - 2⁷ = 89681 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (89819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 44904 + 44905.

It is an arithmetic number, because the mean of its divisors is an integer number (44905).

2⁸⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

89809 is a deficient number, since it is larger than the sum of its proper divisors (1).

89809 is an equidigital number, since it uses as much as digits as its factorization.

89809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 89809 is about 299.6814975937. The cubic root of 89809 is about 44.7823232239.

Subtracting 89809 from its reverse (90898), we obtain a square (1089 = 33²).

It can be divided in two parts, 89 and 809, that added together give a palindrome (898).

The spelling of 89809 in words is "eighty-nine thousand, eight hundred nine".