81043357824 has 768 divisors, whose sum is σ = 286301433600. Its totient is φ = 21805056000.

The previous prime is 81043357807. The next prime is 81043357849. The reversal of 81043357824 is 42875334018.

81043357824 is a `hidden beast` number, since 8 + 10 + 43 + 3 + 578 + 24 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 81043357824.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1141455709 + ... + 1141455779.

It is an arithmetic number, because the mean of its divisors is an integer number (372788325).

Almost surely, 2^81043357824 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 81043357824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143150716800).

81043357824 is an abundant number, since it is smaller than the sum of its proper divisors (205258075776).

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

81043357824 is a wasteful number, since it uses less digits than its factorization.

81043357824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 81043357824 in words is "eighty-one billion, forty-three million, three hundred fifty-seven thousand, eight hundred twenty-four".