81928219020 has 48 divisors (see below), whose sum is σ = 229658956800. Its totient is φ = 21822768576.

The previous prime is 81928219019. The next prime is 81928219073. The reversal of 81928219020 is 2091282918.

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 15 ways as a sum of consecutive naturals, for example, 720220 + ... + 826179.

It is an arithmetic number, because the mean of its divisors is an integer number (4784561600).

Almost surely, 2^81928219020 is an apocalyptic number.

It is an amenable number.

81928219020 is an abundant number, since it is smaller than the sum of its proper divisors (147730737780).

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

81928219020 is a wasteful number, since it uses less digits than its factorization.

81928219020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547294 (or 1547292 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The spelling of 81928219020 in words is "eighty-one billion, nine hundred twenty-eight million, two hundred nineteen thousand, twenty".