91937812823 has 4 divisors (see below), whose sum is σ = 91938502440. Its totient is φ = 91937123208.

The previous prime is 91937812817. The next prime is 91937812843. The reversal of 91937812823 is 32821873919.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 32821873919 = 14149 ⋅2319731.

It is a cyclic number.

It is not a de Polignac number, because 91937812823 - 2¹⁰ = 91937811799 is a prime.

It is a super-2 number, since 2×91937812823² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91937812843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73865 + ... + 435122.

It is an arithmetic number, because the mean of its divisors is an integer number (22984625610).

Almost surely, 2^91937812823 is an apocalyptic number.

91937812823 is a deficient number, since it is larger than the sum of its proper divisors (689617).

91937812823 is a wasteful number, since it uses less digits than its factorization.

91937812823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689616.

The product of its digits is 1306368, while the sum is 53.

The spelling of 91937812823 in words is "ninety-one billion, nine hundred thirty-seven million, eight hundred twelve thousand, eight hundred twenty-three".