81945020832 has 48 divisors (see below), whose sum is σ = 215123120352. Its totient is φ = 27312792320.

The previous prime is 81945020783. The next prime is 81945020917. The reversal of 81945020832 is 23802054918.

It is a tau number, because it is divible by the number of its divisors (48).

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, 1515283 + ... + 1568429.

It is an arithmetic number, because the mean of its divisors is an integer number (4481731674).

Almost surely, 2^81945020832 is an apocalyptic number.

It is an amenable number.

81945020832 is an abundant number, since it is smaller than the sum of its proper divisors (133178099520).

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

81945020832 is a wasteful number, since it uses less digits than its factorization.

81945020832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69221 (or 69213 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 81945020832 in words is "eighty-one billion, nine hundred forty-five million, twenty thousand, eight hundred thirty-two".