91089 has 12 divisors (see below), whose sum is σ = 136500. Its totient is φ = 58464.

The previous prime is 91081. The next prime is 91097. The reversal of 91089 is 98019.

It is an interprime number because it is at equal distance from previous prime (91081) and next prime (91097).

It can be written as a sum of positive squares in 2 ways, for example, as 57600 + 33489 = 240^2 + 183^2 .

It is not a de Polignac number, because 91089 - 2³ = 91081 is a prime.

It is a Curzon number.

91089 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (91081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 87 + ... + 435.

It is an arithmetic number, because the mean of its divisors is an integer number (11375).

2⁹¹⁰⁸⁹ is an apocalyptic number.

It is an amenable number.

91089 is a deficient number, since it is larger than the sum of its proper divisors (45411).

91089 is a wasteful number, since it uses less digits than its factorization.

91089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384 (or 381 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 91089 is about 301.8095425927. The cubic root of 91089 is about 44.9940732935.

It can be divided in two parts, 910 and 89, that added together give a palindrome (999).

The spelling of 91089 in words is "ninety-one thousand, eighty-nine".