91864172181 has 16 divisors (see below), whose sum is σ = 122971305600. Its totient is φ = 61000313088.

The previous prime is 91864172167. The next prime is 91864172207. The reversal of 91864172181 is 18127146819.

It is not a de Polignac number, because 91864172181 - 2¹⁸ = 91863910037 is a prime.

It is a super-2 number, since 2×91864172181² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91864172181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91864176181) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 873225 + ... + 972753.

It is an arithmetic number, because the mean of its divisors is an integer number (7685706600).

Almost surely, 2^91864172181 is an apocalyptic number.

It is an amenable number.

91864172181 is a deficient number, since it is larger than the sum of its proper divisors (31107133419).

91864172181 is a wasteful number, since it uses less digits than its factorization.

91864172181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100748.

The product of its digits is 193536, while the sum is 48.

The spelling of 91864172181 in words is "ninety-one billion, eight hundred sixty-four million, one hundred seventy-two thousand, one hundred eighty-one".