81840084 has 12 divisors (see below), whose sum is σ = 190960224. Its totient is φ = 27280024.

The previous prime is 81840079. The next prime is 81840097. The reversal of 81840084 is 48004818.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3409992 + ... + 3410015.

It is an arithmetic number, because the mean of its divisors is an integer number (15913352).

Almost surely, 2^81840084 is an apocalyptic number.

It is an amenable number.

81840084 is an abundant number, since it is smaller than the sum of its proper divisors (109120140).

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

81840084 is a wasteful number, since it uses less digits than its factorization.

81840084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6820014 (or 6820012 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 33.

The square root of 81840084 is about 9046.5509449734. The cubic root of 81840084 is about 434.1655452332.

The spelling of 81840084 in words is "eighty-one million, eight hundred forty thousand, eighty-four".