91165961871 has 12 divisors (see below), whose sum is σ = 131945971248. Its totient is φ = 60656475264.

The previous prime is 91165961827. The next prime is 91165961903. The reversal of 91165961871 is 17816956119.

It is a happy number.

91165961871 is a `hidden beast` number, since 9 + 1 + 16 + 5 + 9 + 618 + 7 + 1 = 666.

It is not a de Polignac number, because 91165961871 - 2²¹ = 91163864719 is a prime.

It is a super-2 number, since 2×91165961871² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91165911871) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10064610 + ... + 10073663.

It is an arithmetic number, because the mean of its divisors is an integer number (10995497604).

Almost surely, 2^91165961871 is an apocalyptic number.

91165961871 is a deficient number, since it is larger than the sum of its proper divisors (40780009377).

91165961871 is a wasteful number, since it uses less digits than its factorization.

91165961871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20138782 (or 20138779 counting only the distinct ones).

The product of its digits is 816480, while the sum is 54.

The spelling of 91165961871 in words is "ninety-one billion, one hundred sixty-five million, nine hundred sixty-one thousand, eight hundred seventy-one".