91438568564 has 48 divisors (see below), whose sum is σ = 192629068800. Its totient is φ = 37923812640.

The previous prime is 91438568539. The next prime is 91438568569. The reversal of 91438568564 is 46586583419.

It is a super-2 number, since 2×91438568564² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91438568569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1032407 + ... + 1117470.

It is an arithmetic number, because the mean of its divisors is an integer number (4013105600).

Almost surely, 2^91438568564 is an apocalyptic number.

It is an amenable number.

91438568564 is an abundant number, since it is smaller than the sum of its proper divisors (101190500236).

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

91438568564 is a wasteful number, since it uses less digits than its factorization.

91438568564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2149933 (or 2149917 counting only the distinct ones).

The product of its digits is 24883200, while the sum is 59.

The spelling of 91438568564 in words is "ninety-one billion, four hundred thirty-eight million, five hundred sixty-eight thousand, five hundred sixty-four".