81992912 has 40 divisors (see below), whose sum is σ = 161671200. Its totient is φ = 40279680.

The previous prime is 81992909. The next prime is 81992927. The reversal of 81992912 is 21929918.

It is a self number, because there is not a number n which added to its sum of digits gives 81992912.

It is a congruent number.

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, 388487 + ... + 388697.

It is an arithmetic number, because the mean of its divisors is an integer number (4041780).

Almost surely, 2^81992912 is an apocalyptic number.

It is an amenable number.

81992912 is a deficient number, since it is larger than the sum of its proper divisors (79678288).

81992912 is a wasteful number, since it uses less digits than its factorization.

81992912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 531 (or 525 counting only the distinct ones).

The product of its digits is 23328, while the sum is 41.

The square root of 81992912 is about 9054.9937603512. The cubic root of 81992912 is about 434.4356304581.

It can be divided in two parts, 8199 and 2912, that added together give a palindrome (11111).

The spelling of 81992912 in words is "eighty-one million, nine hundred ninety-two thousand, nine hundred twelve".