81542870500 has 192 divisors, whose sum is σ = 224538402816. Its totient is φ = 25176960000.

The previous prime is 81542870491. The next prime is 81542870533. The reversal of 81542870500 is 507824518.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1843645 + ... + 1887355.

It is an arithmetic number, because the mean of its divisors is an integer number (1169470848).

Almost surely, 2^81542870500 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 81542870500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112269201408).

81542870500 is an abundant number, since it is smaller than the sum of its proper divisors (142995532316).

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

81542870500 is a wasteful number, since it uses less digits than its factorization.

81542870500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43791 (or 43779 counting only the distinct ones).

The product of its (nonzero) digits is 89600, while the sum is 40.

The spelling of 81542870500 in words is "eighty-one billion, five hundred forty-two million, eight hundred seventy thousand, five hundred".