91855120771 has 4 divisors (see below), whose sum is σ = 91896480544. Its totient is φ = 91813761000.

The previous prime is 91855120751. The next prime is 91855120787. The reversal of 91855120771 is 17702155819.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91855120771 - 2³⁵ = 57495382403 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91855120751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20676555 + ... + 20680996.

It is an arithmetic number, because the mean of its divisors is an integer number (22974120136).

Almost surely, 2^91855120771 is an apocalyptic number.

91855120771 is a deficient number, since it is larger than the sum of its proper divisors (41359773).

91855120771 is a wasteful number, since it uses less digits than its factorization.

91855120771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41359772.

The product of its (nonzero) digits is 176400, while the sum is 46.

The spelling of 91855120771 in words is "ninety-one billion, eight hundred fifty-five million, one hundred twenty thousand, seven hundred seventy-one".