81966933966918 has 64 divisors (see below), whose sum is σ = 220107011507712. Its totient is φ = 19652411738880.

The previous prime is 81966933966913. The next prime is 81966933966947.

81966933966918 is nontrivially palindromic in base 10.

81966933966918 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81966933966913) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6823748071 + ... + 6823760082.

It is an arithmetic number, because the mean of its divisors is an integer number (3439172054808).

Almost surely, 2^{81966933966918} is an apocalyptic number.

81966933966918 is an abundant number, since it is smaller than the sum of its proper divisors (138140077540794).

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

81966933966918 is a wasteful number, since it uses less digits than its factorization.

81966933966918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13647508189.

The product of its digits is 4897760256, while the sum is 84.

The spelling of 81966933966918 in words is "eighty-one trillion, nine hundred sixty-six billion, nine hundred thirty-three million, nine hundred sixty-six thousand, nine hundred eighteen".