81542583532800 has 1728 divisors, whose sum is σ = 330806614521600. Its totient is φ = 19526477414400.

The previous prime is 81542583532789. The next prime is 81542583532829. The reversal of 81542583532800 is 823538524518.

It is a happy number.

81542583532800 is a `hidden beast` number, since 8 + 1 + 5 + 4 + 2 + 5 + 8 + 353 + 280 + 0 = 666.

81542583532800 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (1728).

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 191 ways as a sum of consecutive naturals, for example, 38590904544 + ... + 38590906656.

Almost surely, 2^{81542583532800} is an apocalyptic number.

81542583532800 is a gapful number since it is divisible by the number (80) 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 81542583532800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165403307260800).

81542583532800 is an abundant number, since it is smaller than the sum of its proper divisors (249264030988800).

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

81542583532800 is a wasteful number, since it uses less digits than its factorization.

81542583532800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2621 (or 2596 counting only the distinct ones).

The product of its (nonzero) digits is 9216000, while the sum is 54.

The spelling of 81542583532800 in words is "eighty-one trillion, five hundred forty-two billion, five hundred eighty-three million, five hundred thirty-two thousand, eight hundred".