81109392 has 160 divisors (see below), whose sum is σ = 266649600. Its totient is φ = 20666880.

The previous prime is 81109373. The next prime is 81109393. The reversal of 81109392 is 29390118.

It is not an unprimeable number, because it can be changed into a prime (81109393) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 135109 + ... + 135707.

It is an arithmetic number, because the mean of its divisors is an integer number (1666560).

Almost surely, 2^81109392 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81109392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133324800).

81109392 is an abundant number, since it is smaller than the sum of its proper divisors (185540208).

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

81109392 is a wasteful number, since it uses less digits than its factorization.

81109392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661 (or 655 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 81109392 is about 9006.0752828299. The cubic root of 81109392 is about 432.8695619493.

The spelling of 81109392 in words is "eighty-one million, one hundred nine thousand, three hundred ninety-two".