81537069878 has 32 divisors (see below), whose sum is σ = 137257970688. Its totient is φ = 36008910400.

The previous prime is 81537069877. The next prime is 81537069907. The reversal of 81537069878 is 87896073518.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81537069878.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81537069877) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 146138 + ... + 429453.

It is an arithmetic number, because the mean of its divisors is an integer number (4289311584).

Almost surely, 2^81537069878 is an apocalyptic number.

81537069878 is a deficient number, since it is larger than the sum of its proper divisors (55720900810).

81537069878 is a wasteful number, since it uses less digits than its factorization.

81537069878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575788.

The product of its (nonzero) digits is 20321280, while the sum is 62.

The spelling of 81537069878 in words is "eighty-one billion, five hundred thirty-seven million, sixty-nine thousand, eight hundred seventy-eight".