91089768 has 96 divisors (see below), whose sum is σ = 286130880. Its totient is φ = 23654400.

The previous prime is 91089727. The next prime is 91089773. The reversal of 91089768 is 86798019.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18088 + ... + 22568.

It is an arithmetic number, because the mean of its divisors is an integer number (2980530).

Almost surely, 2^91089768 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 91089768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143065440).

91089768 is an abundant number, since it is smaller than the sum of its proper divisors (195041112).

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

91089768 is a wasteful number, since it uses less digits than its factorization.

91089768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4519 (or 4504 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 91089768 is about 9544.0959760472. The cubic root of 91089768 is about 449.9419974624.

The spelling of 91089768 in words is "ninety-one million, eighty-nine thousand, seven hundred sixty-eight".