81605107584000 has 4224 divisors, whose sum is σ = 409614932772864. Its totient is φ = 15646556160000.

The previous prime is 81605107583963. The next prime is 81605107584017. The reversal of 81605107584000 is 48570150618.

81605107584000 is a `hidden beast` number, since 8 + 1 + 60 + 5 + 1 + 0 + 7 + 584 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (4224).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 383 ways as a sum of consecutive naturals, for example, 31135102690 + ... + 31135105310.

Almost surely, 2^{81605107584000} is an apocalyptic number.

81605107584000 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 81605107584000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (204807466386432).

81605107584000 is an abundant number, since it is smaller than the sum of its proper divisors (328009825188864).

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

81605107584000 is a wasteful number, since it uses less digits than its factorization.

81605107584000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2702 (or 2662 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 45.

The spelling of 81605107584000 in words is "eighty-one trillion, six hundred five billion, one hundred seven million, five hundred eighty-four thousand".