81403866432 has 112 divisors (see below), whose sum is σ = 273499803520. Its totient is φ = 23258244096.

The previous prime is 81403866373. The next prime is 81403866451. The reversal of 81403866432 is 23466830418.

81403866432 is a `hidden beast` number, since 81 + 403 + 86 + 64 + 32 = 666.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3352813 + ... + 3377004.

Almost surely, 2^81403866432 is an apocalyptic number.

It is an amenable number.

81403866432 is an abundant number, since it is smaller than the sum of its proper divisors (192095937088).

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

81403866432 is a wasteful number, since it uses less digits than its factorization.

81403866432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6729845 (or 6729829 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The spelling of 81403866432 in words is "eighty-one billion, four hundred three million, eight hundred sixty-six thousand, four hundred thirty-two".