81613351374912 has 1008 divisors, whose sum is σ = 294690153051840. Its totient is φ = 21457000341504.

The previous prime is 81613351374911. The next prime is 81613351374913. The reversal of 81613351374912 is 21947315331618.

81613351374912 is a `hidden beast` number, since 8 + 1 + 6 + 1 + 33 + 513 + 7 + 4 + 91 + 2 = 666.

81613351374912 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (81613351374911) and next prime (81613351374913).

It is a tau number, because it is divible by the number of its divisors (1008).

It is not an unprimeable number, because it can be changed into a prime (81613351374911) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 12758063298 + ... + 12758069694.

Almost surely, 2^{81613351374912} 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 81613351374912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147345076525920).

81613351374912 is an abundant number, since it is smaller than the sum of its proper divisors (213076801676928).

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

81613351374912 is a wasteful number, since it uses less digits than its factorization.

81613351374912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7128 (or 7108 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 54.

The spelling of 81613351374912 in words is "eighty-one trillion, six hundred thirteen billion, three hundred fifty-one million, three hundred seventy-four thousand, nine hundred twelve".