91191275664 has 80 divisors (see below), whose sum is σ = 242505228672. Its totient is φ = 29506996224.

The previous prime is 91191275653. The next prime is 91191275687. The reversal of 91191275664 is 46657219119.

It is a happy number.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 709717 + ... + 828299.

Almost surely, 2^91191275664 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 91191275664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121252614336).

91191275664 is an abundant number, since it is smaller than the sum of its proper divisors (151313953008).

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

91191275664 is a wasteful number, since it uses less digits than its factorization.

91191275664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119064 (or 119058 counting only the distinct ones).

The product of its digits is 816480, while the sum is 51.

The spelling of 91191275664 in words is "ninety-one billion, one hundred ninety-one million, two hundred seventy-five thousand, six hundred sixty-four".