91788 has 12 divisors (see below), whose sum is σ = 214200. Its totient is φ = 30592.

The previous prime is 91781. The next prime is 91801. The reversal of 91788 is 88719.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a plaindrome in base 16.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91788.

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, 3813 + ... + 3836.

It is an arithmetic number, because the mean of its divisors is an integer number (17850).

2⁹¹⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

91788 is an abundant number, since it is smaller than the sum of its proper divisors (122412).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107100).

91788 is a wasteful number, since it uses less digits than its factorization.

91788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7656 (or 7654 counting only the distinct ones).

The product of its digits is 4032, while the sum is 33.

The square root of 91788 is about 302.9653445528. The cubic root of 91788 is about 45.1088721866.

The spelling of 91788 in words is "ninety-one thousand, seven hundred eighty-eight".