91165859172 has 72 divisors (see below), whose sum is σ = 231461726496. Its totient is φ = 30255047424.

The previous prime is 91165859171. The next prime is 91165859179. The reversal of 91165859172 is 27195856119.

It is a happy number.

It is a super-2 number, since 2×91165859172² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91165859171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10793583 + ... + 10802025.

Almost surely, 2^91165859172 is an apocalyptic number.

It is an amenable number.

91165859172 is an abundant number, since it is smaller than the sum of its proper divisors (140295867324).

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

91165859172 is a wasteful number, since it uses less digits than its factorization.

91165859172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9737 (or 9732 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 54.

The spelling of 91165859172 in words is "ninety-one billion, one hundred sixty-five million, eight hundred fifty-nine thousand, one hundred seventy-two".