81912084 has 12 divisors (see below), whose sum is σ = 191128224. Its totient is φ = 27304024.

The previous prime is 81912071. The next prime is 81912109. The reversal of 81912084 is 48021918.

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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3412992 + ... + 3413015.

It is an arithmetic number, because the mean of its divisors is an integer number (15927352).

Almost surely, 2^81912084 is an apocalyptic number.

It is an amenable number.

81912084 is an abundant number, since it is smaller than the sum of its proper divisors (109216140).

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

81912084 is a wasteful number, since it uses less digits than its factorization.

81912084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6826014 (or 6826012 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 81912084 is about 9050.5294872731. The cubic root of 81912084 is about 434.2928290575.

The spelling of 81912084 in words is "eighty-one million, nine hundred twelve thousand, eighty-four".