81752509800 has 288 divisors, whose sum is σ = 299842058880. Its totient is φ = 19839859200.

The previous prime is 81752509793. The next prime is 81752509849. The reversal of 81752509800 is 890525718.

It is a happy number.

81752509800 is a `hidden beast` number, since 8 + 17 + 52 + 509 + 80 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1636797 + ... + 1686003.

It is an arithmetic number, because the mean of its divisors is an integer number (1041118260).

Almost surely, 2^81752509800 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 81752509800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149921029440).

81752509800 is an abundant number, since it is smaller than the sum of its proper divisors (218089549080).

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

81752509800 is a wasteful number, since it uses less digits than its factorization.

81752509800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49313 (or 49301 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 45.

The spelling of 81752509800 in words is "eighty-one billion, seven hundred fifty-two million, five hundred nine thousand, eight hundred".