81757511568000 has 2048 divisors, whose sum is σ = 325373158656000. Its totient is φ = 20125974528000.

The previous prime is 81757511567957. The next prime is 81757511568037. The reversal of 81757511568000 is 86511575718.

81757511568000 is a `hidden beast` number, since 8 + 1 + 7 + 5 + 75 + 1 + 1 + 568 + 0 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 39515470966 + ... + 39515473034.

It is an arithmetic number, because the mean of its divisors is an integer number (158873612625).

Almost surely, 2^{81757511568000} is an apocalyptic number.

81757511568000 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 81757511568000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (162686579328000).

81757511568000 is an abundant number, since it is smaller than the sum of its proper divisors (243615647088000).

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

81757511568000 is a wasteful number, since it uses less digits than its factorization.

81757511568000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2268 (or 2240 counting only the distinct ones).

The product of its (nonzero) digits is 2352000, while the sum is 54.

The spelling of 81757511568000 in words is "eighty-one trillion, seven hundred fifty-seven billion, five hundred eleven million, five hundred sixty-eight thousand".