91789 has 4 divisors (see below), whose sum is σ = 96640. Its totient is φ = 86940.

The previous prime is 91781. The next prime is 91801. The reversal of 91789 is 98719.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98719 = 17 ⋅5807.

It is a cyclic number.

It is not a de Polignac number, because 91789 - 2³ = 91781 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2397 + ... + 2434.

It is an arithmetic number, because the mean of its divisors is an integer number (24160).

2⁹¹⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

91789 is a deficient number, since it is larger than the sum of its proper divisors (4851).

91789 is a wasteful number, since it uses less digits than its factorization.

91789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4850.

The product of its digits is 4536, while the sum is 34.

The square root of 91789 is about 302.9669949021. The cubic root of 91789 is about 45.1090360015.

The spelling of 91789 in words is "ninety-one thousand, seven hundred eighty-nine".