91181868 has 48 divisors (see below), whose sum is σ = 219135840. Its totient is φ = 29491200.

The previous prime is 91181813. The next prime is 91181873. The reversal of 91181868 is 86818119.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 118188 + ... + 118956.

It is an arithmetic number, because the mean of its divisors is an integer number (4565330).

Almost surely, 2^91181868 is an apocalyptic number.

It is an amenable number.

91181868 is an abundant number, since it is smaller than the sum of its proper divisors (127953972).

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

91181868 is a wasteful number, since it uses less digits than its factorization.

91181868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058 (or 1056 counting only the distinct ones).

The product of its digits is 27648, while the sum is 42.

The square root of 91181868 is about 9548.9197294773. The cubic root of 91181868 is about 450.0935904104.

The spelling of 91181868 in words is "ninety-one million, one hundred eighty-one thousand, eight hundred sixty-eight".