81344540160000 has 1560 divisors, whose sum is σ = 318268980949920. Its totient is φ = 20010811392000.

The previous prime is 81344540159989. The next prime is 81344540160031. The reversal of 81344540160000 is 6104544318.

81344540160000 is a `hidden beast` number, since 8 + 1 + 3 + 4 + 4 + 5 + 40 + 1 + 600 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1560).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 119 ways as a sum of consecutive naturals, for example, 50618879197 + ... + 50618880803.

It is an arithmetic number, because the mean of its divisors is an integer number (204018577532).

Almost surely, 2^{81344540160000} is an apocalyptic number.

81344540160000 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 81344540160000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159134490474960).

81344540160000 is an abundant number, since it is smaller than the sum of its proper divisors (236924440789920).

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

81344540160000 is an equidigital number, since it uses as much as digits as its factorization.

81344540160000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1696 (or 1630 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 81344540160000 in words is "eighty-one trillion, three hundred forty-four billion, five hundred forty million, one hundred sixty thousand".