81575838432 has 288 divisors, whose sum is σ = 264574791936. Its totient is φ = 23600332800.

The previous prime is 81575838419. The next prime is 81575838433. The reversal of 81575838432 is 23483857518.

81575838432 is a `hidden beast` number, since 8 + 1 + 57 + 583 + 8 + 4 + 3 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81575838433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 70750368 + ... + 70751520.

It is an arithmetic number, because the mean of its divisors is an integer number (918662472).

Almost surely, 2^81575838432 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 81575838432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132287395968).

81575838432 is an abundant number, since it is smaller than the sum of its proper divisors (182998953504).

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

81575838432 is a wasteful number, since it uses less digits than its factorization.

81575838432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2174 (or 2163 counting only the distinct ones).

The product of its digits is 6451200, while the sum is 54.

The spelling of 81575838432 in words is "eighty-one billion, five hundred seventy-five million, eight hundred thirty-eight thousand, four hundred thirty-two".