81709954560000 has 3120 divisors, whose sum is σ = 343696968014400. Its totient is φ = 18529910784000.

The previous prime is 81709954559939. The next prime is 81709954560053. The reversal of 81709954560000 is 6545990718.

81709954560000 is a `hidden beast` number, since 8 + 1 + 7 + 0 + 99 + 545 + 6 + 0 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 199779839796 + ... + 199779840204.

It is an arithmetic number, because the mean of its divisors is an integer number (110159284620).

Almost surely, 2^{81709954560000} is an apocalyptic number.

81709954560000 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 81709954560000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171848484007200).

81709954560000 is an abundant number, since it is smaller than the sum of its proper divisors (261987013454400).

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

81709954560000 is a wasteful number, since it uses less digits than its factorization.

81709954560000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524 (or 484 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 54.

The spelling of 81709954560000 in words is "eighty-one trillion, seven hundred nine billion, nine hundred fifty-four million, five hundred sixty thousand".