81582336 has 288 divisors, whose sum is σ = 279619200. Its totient is φ = 23224320.

The previous prime is 81582323. The next prime is 81582341. The reversal of 81582336 is 63328518.

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

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

It is a self number, because there is not a number n which added to its sum of digits gives 81582336.

It is a congruent number.

It is an unprimeable number.

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, 2204910 + ... + 2204946.

It is an arithmetic number, because the mean of its divisors is an integer number (970900).

Almost surely, 2^81582336 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 81582336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139809600).

81582336 is an abundant number, since it is smaller than the sum of its proper divisors (198036864).

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

81582336 is a wasteful number, since it uses less digits than its factorization.

81582336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 82 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81582336 is about 9032.2940607578. The cubic root of 81582336 is about 433.7092774322.

It can be divided in two parts, 81582 and 336, that added together give a palindrome (81918).

The spelling of 81582336 in words is "eighty-one million, five hundred eighty-two thousand, three hundred thirty-six".