81316049338368 has 2160 divisors, whose sum is σ = 288497447325360. Its totient is φ = 21851384315904.

The previous prime is 81316049338319. The next prime is 81316049338387. The reversal of 81316049338368 is 86383394061318.

81316049338368 is a `hidden beast` number, since 8 + 1 + 3 + 1 + 6 + 0 + 493 + 3 + 83 + 68 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 795721089024 + 80520328249344 = 892032^2 + 8973312^2 .

It is a super-2 number, since 2×81316049338368² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 913663475668 + ... + 913663475756.

It is an arithmetic number, because the mean of its divisors is an integer number (133563633021).

Almost surely, 2^{81316049338368} 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 81316049338368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144248723662680).

81316049338368 is an abundant number, since it is smaller than the sum of its proper divisors (207181397986992).

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

81316049338368 is a wasteful number, since it uses less digits than its factorization.

81316049338368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 53747712, while the sum is 63.

The spelling of 81316049338368 in words is "eighty-one trillion, three hundred sixteen billion, forty-nine million, three hundred thirty-eight thousand, three hundred sixty-eight".