91005505056 has 144 divisors (see below), whose sum is σ = 281812003200. Its totient is φ = 27747546624.

The previous prime is 91005505039. The next prime is 91005505057. The reversal of 91005505056 is 65050550019.

91005505056 is a `hidden beast` number, since 9 + 1 + 0 + 0 + 550 + 50 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a self number, because there is not a number n which added to its sum of digits gives 91005505056.

It is not an unprimeable number, because it can be changed into a prime (91005505057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 128056 + ... + 445431.

It is an arithmetic number, because the mean of its divisors is an integer number (1957027800).

Almost surely, 2^91005505056 is an apocalyptic number.

91005505056 is a gapful number since it is divisible by the number (96) formed by its first and last digit.

It is an amenable number.

91005505056 is an abundant number, since it is smaller than the sum of its proper divisors (190806498144).

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

91005505056 is a wasteful number, since it uses less digits than its factorization.

91005505056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573551 (or 573540 counting only the distinct ones).

The product of its (nonzero) digits is 33750, while the sum is 36.

The spelling of 91005505056 in words is "ninety-one billion, five million, five hundred five thousand, fifty-six".