81932007840 has 96 divisors (see below), whose sum is σ = 260118190080. Its totient is φ = 21676483584.

The previous prime is 81932007827. The next prime is 81932007851. The reversal of 81932007840 is 4870023918.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 81932007792 and 81932007801.

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, 611055 + ... + 732974.

It is an arithmetic number, because the mean of its divisors is an integer number (2709564480).

Almost surely, 2^81932007840 is an apocalyptic number.

81932007840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81932007840 is an abundant number, since it is smaller than the sum of its proper divisors (178186182240).

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

81932007840 is a wasteful number, since it uses less digits than its factorization.

81932007840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344174 (or 1344166 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 42.

The spelling of 81932007840 in words is "eighty-one billion, nine hundred thirty-two million, seven thousand, eight hundred forty".