91389186681 has 16 divisors (see below), whose sum is σ = 133701454656. Its totient is φ = 55178375616.

The previous prime is 91389186661. The next prime is 91389186739. The reversal of 91389186681 is 18668198319.

It is not a de Polignac number, because 91389186681 - 2⁹ = 91389186169 is a prime.

It is a super-2 number, since 2×91389186681² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (91389186661) 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, 22104655 + ... + 22108788.

It is an arithmetic number, because the mean of its divisors is an integer number (8356340916).

Almost surely, 2^91389186681 is an apocalyptic number.

It is an amenable number.

91389186681 is a deficient number, since it is larger than the sum of its proper divisors (42312267975).

91389186681 is a wasteful number, since it uses less digits than its factorization.

91389186681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44213512.

The product of its digits is 4478976, while the sum is 60.

The spelling of 91389186681 in words is "ninety-one billion, three hundred eighty-nine million, one hundred eighty-six thousand, six hundred eighty-one".