81257638126896 has 1600 divisors, whose sum is σ = 319419037301760. Its totient is φ = 19293278699520.

The previous prime is 81257638126883. The next prime is 81257638126901. The reversal of 81257638126896 is 69862183675218.

81257638126896 is a `hidden beast` number, since 8 + 1 + 2 + 576 + 38 + 12 + 6 + 8 + 9 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

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 319 ways as a sum of consecutive naturals, for example, 63334089871 + ... + 63334091153.

Almost surely, 2^{81257638126896} 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 81257638126896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159709518650880).

81257638126896 is an abundant number, since it is smaller than the sum of its proper divisors (238161399174864).

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

81257638126896 is a wasteful number, since it uses less digits than its factorization.

81257638126896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2384 (or 2369 counting only the distinct ones).

The product of its digits is 418037760, while the sum is 72.

The spelling of 81257638126896 in words is "eighty-one trillion, two hundred fifty-seven billion, six hundred thirty-eight million, one hundred twenty-six thousand, eight hundred ninety-six".