91008 has 48 divisors (see below), whose sum is σ = 265200. Its totient is φ = 29952.

The previous prime is 90997. The next prime is 91009. The reversal of 91008 is 80019.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91009) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1113 + ... + 1191.

It is an arithmetic number, because the mean of its divisors is an integer number (5525).

2⁹¹⁰⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132600).

91008 is an abundant number, since it is smaller than the sum of its proper divisors (174192).

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

91008 is a wasteful number, since it uses less digits than its factorization.

91008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 91008 is about 301.6753221594. The cubic root of 91008 is about 44.9807324922.

The spelling of 91008 in words is "ninety-one thousand, eight".