81798606584856 has 192 divisors, whose sum is σ = 259127070808320. Its totient is φ = 22822860775680.

The previous prime is 81798606584797. The next prime is 81798606584953. The reversal of 81798606584856 is 65848560689718.

81798606584856 is a `hidden beast` number, since 8 + 1 + 7 + 9 + 86 + 0 + 6 + 58 + 485 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 106525411 + ... + 107290541.

It is an arithmetic number, because the mean of its divisors is an integer number (1349620160460).

Almost surely, 2^{81798606584856} is an apocalyptic number.

81798606584856 is a gapful number since it is divisible by the number (86) 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 81798606584856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129563535404160).

81798606584856 is an abundant number, since it is smaller than the sum of its proper divisors (177328464223464).

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

81798606584856 is a wasteful number, since it uses less digits than its factorization.

81798606584856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770126 (or 770119 counting only the distinct ones).

The product of its (nonzero) digits is 5573836800, while the sum is 81.

The spelling of 81798606584856 in words is "eighty-one trillion, seven hundred ninety-eight billion, six hundred six million, five hundred eighty-four thousand, eight hundred fifty-six".