81033638894 has 16 divisors (see below), whose sum is σ = 130941649440. Its totient is φ = 37388382240.

The previous prime is 81033638879. The next prime is 81033638921. The reversal of 81033638894 is 49883633018.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405389 + ... + 571320.

It is an arithmetic number, because the mean of its divisors is an integer number (8183853090).

Almost surely, 2^81033638894 is an apocalyptic number.

81033638894 is a deficient number, since it is larger than the sum of its proper divisors (49908010546).

81033638894 is a wasteful number, since it uses less digits than its factorization.

81033638894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979915.

The product of its (nonzero) digits is 2985984, while the sum is 53.

The spelling of 81033638894 in words is "eighty-one billion, thirty-three million, six hundred thirty-eight thousand, eight hundred ninety-four".