91591574881 has 9 divisors (see below), whose sum is σ = 92357203761. Its totient is φ = 90832248612.

The previous prime is 91591574869. The next prime is 91591574887. The reversal of 91591574881 is 18847519519.

The square root of 91591574881 is 302641.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 91591574881 - 2¹⁵ = 91591542113 is a prime.

It is a super-2 number, since 2×91591574881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91591574887) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 38434216 + ... + 38436598.

It is an arithmetic number, because the mean of its divisors is an integer number (10261911529).

Almost surely, 2^91591574881 is an apocalyptic number.

91591574881 is the 302641-st square number.

91591574881 is the 151321-st centered octagonal number.

It is an amenable number.

91591574881 is a deficient number, since it is larger than the sum of its proper divisors (765628880).

91591574881 is an frugal number, since it uses more digits than its factorization.

91591574881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5020 (or 2510 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 58.

The spelling of 91591574881 in words is "ninety-one billion, five hundred ninety-one million, five hundred seventy-four thousand, eight hundred eighty-one".