81056563200 has 612 divisors, whose sum is σ = 304252490880. Its totient is φ = 20588789760.

The previous prime is 81056563183. The next prime is 81056563213. The reversal of 81056563200 is 236565018.

81056563200 is a `hidden beast` number, since 8 + 10 + 5 + 6 + 5 + 632 + 0 + 0 = 666.

It is a super-3 number, since 3×81056563200³ (a number of 34 digits) contains 333 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 339148681 + ... + 339148919.

Almost surely, 2^81056563200 is an apocalyptic number.

81056563200 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 81056563200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152126245440).

81056563200 is an abundant number, since it is smaller than the sum of its proper divisors (223195927680).

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

81056563200 is a wasteful number, since it uses less digits than its factorization.

81056563200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 272 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 81056563200 in words is "eighty-one billion, fifty-six million, five hundred sixty-three thousand, two hundred".