81601678992960 has 336 divisors, whose sum is σ = 320818251936000. Its totient is φ = 18649141235712.

The previous prime is 81601678992931. The next prime is 81601678993001. The reversal of 81601678992960 is 6929987610618.

81601678992960 is a `hidden beast` number, since 8 + 1 + 601 + 6 + 7 + 8 + 9 + 9 + 2 + 9 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

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 47 ways as a sum of consecutive naturals, for example, 142224741 + ... + 142797339.

It is an arithmetic number, because the mean of its divisors is an integer number (954816226000).

Almost surely, 2^{81601678992960} is an apocalyptic number.

81601678992960 is a gapful number since it is divisible by the number (80) 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 81601678992960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160409125968000).

81601678992960 is an abundant number, since it is smaller than the sum of its proper divisors (239216572943040).

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

81601678992960 is a wasteful number, since it uses less digits than its factorization.

81601678992960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579698 (or 579685 counting only the distinct ones).

The product of its (nonzero) digits is 141087744, while the sum is 72.

The spelling of 81601678992960 in words is "eighty-one trillion, six hundred one billion, six hundred seventy-eight million, nine hundred ninety-two thousand, nine hundred sixty".