91091088 has 160 divisors (see below), whose sum is σ = 295516800. Its totient is φ = 26611200.

The previous prime is 91091081. The next prime is 91091129. The reversal of 91091088 is 88019019.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (91091081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137478 + ... + 138138.

It is an arithmetic number, because the mean of its divisors is an integer number (1846980).

Almost surely, 2^91091088 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 91091088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147758400).

91091088 is an abundant number, since it is smaller than the sum of its proper divisors (204425712).

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

91091088 is a wasteful number, since it uses less digits than its factorization.

91091088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718 (or 706 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 91091088 is about 9544.1651284960. The cubic root of 91091088 is about 449.9441708516.

The spelling of 91091088 in words is "ninety-one million, ninety-one thousand, eighty-eight".