91565911423 has 4 divisors (see below), whose sum is σ = 104646755920. Its totient is φ = 78485066928.

The previous prime is 91565911421. The next prime is 91565911441. The reversal of 91565911423 is 32411956519.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91565911423 - 2¹ = 91565911421 is a prime.

It is a super-2 number, since 2×91565911423² (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 (91565911421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6540422238 + ... + 6540422251.

It is an arithmetic number, because the mean of its divisors is an integer number (26161688980).

Almost surely, 2^91565911423 is an apocalyptic number.

91565911423 is a deficient number, since it is larger than the sum of its proper divisors (13080844497).

91565911423 is a wasteful number, since it uses less digits than its factorization.

91565911423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13080844496.

The product of its digits is 291600, while the sum is 46.

The spelling of 91565911423 in words is "ninety-one billion, five hundred sixty-five million, nine hundred eleven thousand, four hundred twenty-three".