81942589728000 has 216 divisors, whose sum is σ = 294853338799656. Its totient is φ = 21851357184000.

The previous prime is 81942589727909. The next prime is 81942589728001. The reversal of 81942589728000 is 82798524918.

81942589728000 is a `hidden beast` number, since 8 + 1 + 9 + 42 + 589 + 7 + 2 + 8 + 0 + 0 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 25211324703744 + 56731265024256 = 5021088^2 + 7532016^2 .

It is a super-2 number, since 2×81942589728000² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81942589728001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 141973441 + ... + 142549440.

Almost surely, 2^{81942589728000} is an apocalyptic number.

81942589728000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81942589728000 is an abundant number, since it is smaller than the sum of its proper divisors (212910749071656).

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

81942589728000 is a wasteful number, since it uses less digits than its factorization.

81942589728000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284522918 (or 284522891 counting only the distinct ones).

The product of its (nonzero) digits is 23224320, while the sum is 63.

The spelling of 81942589728000 in words is "eighty-one trillion, nine hundred forty-two billion, five hundred eighty-nine million, seven hundred twenty-eight thousand".