81238926924 has 36 divisors (see below), whose sum is σ = 216162058840. Its totient is φ = 25654397760.

The previous prime is 81238926893. The next prime is 81238926947. The reversal of 81238926924 is 42962983218.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59384497 + ... + 59385864.

Almost surely, 2^81238926924 is an apocalyptic number.

It is an amenable number.

81238926924 is an abundant number, since it is smaller than the sum of its proper divisors (134923131916).

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

81238926924 is a wasteful number, since it uses less digits than its factorization.

81238926924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118770390 (or 118770385 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The spelling of 81238926924 in words is "eighty-one billion, two hundred thirty-eight million, nine hundred twenty-six thousand, nine hundred twenty-four".