91386155521 has 16 divisors (see below), whose sum is σ = 98516822400. Its totient is φ = 84511728000.

The previous prime is 91386155501. The next prime is 91386155527. The reversal of 91386155521 is 12555168319.

It is a cyclic number.

It is not a de Polignac number, because 91386155521 - 2¹⁵ = 91386122753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91386155527) 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, 199116 + ... + 471613.

It is an arithmetic number, because the mean of its divisors is an integer number (6157301400).

Almost surely, 2^91386155521 is an apocalyptic number.

It is an amenable number.

91386155521 is a deficient number, since it is larger than the sum of its proper divisors (7130666879).

91386155521 is a wasteful number, since it uses less digits than its factorization.

91386155521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670920.

The product of its digits is 324000, while the sum is 46.

The spelling of 91386155521 in words is "ninety-one billion, three hundred eighty-six million, one hundred fifty-five thousand, five hundred twenty-one".