81504589824 has 720 divisors, whose sum is σ = 291921870240. Its totient is φ = 22574039040.

The previous prime is 81504589739. The next prime is 81504589843. The reversal of 81504589824 is 42898540518.

81504589824 is a `hidden beast` number, since 8 + 1 + 50 + 4 + 589 + 8 + 2 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 300754809 + ... + 300755079.

It is an arithmetic number, because the mean of its divisors is an integer number (405447042).

Almost surely, 2^81504589824 is an apocalyptic number.

81504589824 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81504589824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145960935120).

81504589824 is an abundant number, since it is smaller than the sum of its proper divisors (210417280416).

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

81504589824 is a wasteful number, since it uses less digits than its factorization.

81504589824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356 (or 320 counting only the distinct ones).

The product of its (nonzero) digits is 3686400, while the sum is 54.

The spelling of 81504589824 in words is "eighty-one billion, five hundred four million, five hundred eighty-nine thousand, eight hundred twenty-four".