81928120432 has 20 divisors (see below), whose sum is σ = 158742112176. Its totient is φ = 40962414080.

The previous prime is 81928120427. The next prime is 81928120471. The reversal of 81928120432 is 23402182918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 374973 + ... + 551779.

Almost surely, 2^81928120432 is an apocalyptic number.

It is an amenable number.

81928120432 is a deficient number, since it is larger than the sum of its proper divisors (76813991744).

81928120432 is a wasteful number, since it uses less digits than its factorization.

81928120432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205776 (or 205770 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 81928120432 in words is "eighty-one billion, nine hundred twenty-eight million, one hundred twenty thousand, four hundred thirty-two".