81788592 has 80 divisors (see below), whose sum is σ = 217271808. Its totient is φ = 26503680.

The previous prime is 81788591. The next prime is 81788599. The reversal of 81788592 is 29588718.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (81788591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 350908 + ... + 351140.

Almost surely, 2^81788592 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 81788592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108635904).

81788592 is an abundant number, since it is smaller than the sum of its proper divisors (135483216).

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

81788592 is a wasteful number, since it uses less digits than its factorization.

81788592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 412 counting only the distinct ones).

The product of its digits is 322560, while the sum is 48.

The square root of 81788592 is about 9043.7045506805. The cubic root of 81788592 is about 434.0744702919.

The spelling of 81788592 in words is "eighty-one million, seven hundred eighty-eight thousand, five hundred ninety-two".