81604832 has 48 divisors (see below), whose sum is σ = 166430880. Its totient is φ = 39356928.

The previous prime is 81604823. The next prime is 81604849. The reversal of 81604832 is 23840618.

It is a Harshad number since it is a multiple of its sum of digits (32).

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, 185669 + ... + 186107.

It is an arithmetic number, because the mean of its divisors is an integer number (3467310).

Almost surely, 2^81604832 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 81604832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83215440).

81604832 is an abundant number, since it is smaller than the sum of its proper divisors (84826048).

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

81604832 is a wasteful number, since it uses less digits than its factorization.

81604832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643 (or 635 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 81604832 is about 9033.5392842451. The cubic root of 81604832 is about 433.7491382964.

The spelling of 81604832 in words is "eighty-one million, six hundred four thousand, eight hundred thirty-two".