81576384 has 56 divisors (see below), whose sum is σ = 218480640. Its totient is φ = 26859264.

The previous prime is 81576361. The next prime is 81576401. The reversal of 81576384 is 48367518.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

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 7 ways as a sum of consecutive naturals, for example, 13377 + ... + 18495.

It is an arithmetic number, because the mean of its divisors is an integer number (3901440).

Almost surely, 2^81576384 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 81576384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109240320).

81576384 is an abundant number, since it is smaller than the sum of its proper divisors (136904256).

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

81576384 is a wasteful number, since it uses less digits than its factorization.

81576384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5217 (or 5207 counting only the distinct ones).

The product of its digits is 161280, while the sum is 42.

The square root of 81576384 is about 9031.9645703468. The cubic root of 81576384 is about 433.6987298041.

It can be divided in two parts, 8157 and 6384, that added together give a palindrome (14541).

The spelling of 81576384 in words is "eighty-one million, five hundred seventy-six thousand, three hundred eighty-four".