81377831823 has 32 divisors (see below), whose sum is σ = 115386009600. Its totient is φ = 50909354496.

The previous prime is 81377831803. The next prime is 81377831893. The reversal of 81377831823 is 32813877318.

It is a Cunningham number, because it is equal to 285268²-1.

It is not a de Polignac number, because 81377831823 - 2⁵ = 81377831791 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81377831803) 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 31 ways as a sum of consecutive naturals, for example, 808263 + ... + 903351.

It is an arithmetic number, because the mean of its divisors is an integer number (3605812800).

Almost surely, 2^81377831823 is an apocalyptic number.

81377831823 is a deficient number, since it is larger than the sum of its proper divisors (34008177777).

81377831823 is a wasteful number, since it uses less digits than its factorization.

81377831823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95351.

The product of its digits is 1354752, while the sum is 51.

The spelling of 81377831823 in words is "eighty-one billion, three hundred seventy-seven million, eight hundred thirty-one thousand, eight hundred twenty-three".