81364246656 has 256 divisors, whose sum is σ = 270975974400. Its totient is φ = 21014138880.

The previous prime is 81364246637. The next prime is 81364246681. The reversal of 81364246656 is 65664246318.

It is a junction number, because it is equal to n+sod(n) for n = 81364246599 and 81364246608.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5284986 + ... + 5300358.

It is an arithmetic number, because the mean of its divisors is an integer number (1058499900).

Almost surely, 2^81364246656 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 81364246656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135487987200).

81364246656 is an abundant number, since it is smaller than the sum of its proper divisors (189611727744).

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

81364246656 is a wasteful number, since it uses less digits than its factorization.

81364246656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15587 (or 15575 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 51.

The spelling of 81364246656 in words is "eighty-one billion, three hundred sixty-four million, two hundred forty-six thousand, six hundred fifty-six".