81344563200 has 864 divisors, whose sum is σ = 317281255200. Its totient is φ = 20424130560.

The previous prime is 81344563163. The next prime is 81344563207. The reversal of 81344563200 is 236544318.

81344563200 is a `hidden beast` number, since 8 + 1 + 3 + 445 + 6 + 3 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (81344563207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 499046319 + ... + 499046481.

It is an arithmetic number, because the mean of its divisors is an integer number (367223675).

Almost surely, 2^81344563200 is an apocalyptic number.

81344563200 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 81344563200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158640627600).

81344563200 is an abundant number, since it is smaller than the sum of its proper divisors (235936692000).

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

81344563200 is a wasteful number, since it uses less digits than its factorization.

81344563200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 192 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 81344563200 in words is "eighty-one billion, three hundred forty-four million, five hundred sixty-three thousand, two hundred".