81765432 has 96 divisors (see below), whose sum is σ = 257942880. Its totient is φ = 22913280.

The previous prime is 81765421. The next prime is 81765433. The reversal of 81765432 is 23456718.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81765433) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25182 + ... + 28242.

It is an arithmetic number, because the mean of its divisors is an integer number (2686905).

Almost surely, 2^81765432 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 81765432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128971440).

81765432 is an abundant number, since it is smaller than the sum of its proper divisors (176177448).

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

81765432 is a wasteful number, since it uses less digits than its factorization.

81765432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3133 (or 3126 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 81765432 is about 9042.4240112925. The cubic root of 81765432 is about 434.0334942685.

The spelling of 81765432 in words is "eighty-one million, seven hundred sixty-five thousand, four hundred thirty-two".