81949109760000 has 3120 divisors, whose sum is σ = 364055325004800. Its totient is φ = 17337286656000.

The previous prime is 81949109759939. The next prime is 81949109760017. The reversal of 81949109760000 is 6790194918.

81949109760000 is a `hidden beast` number, since 8 + 1 + 9 + 491 + 0 + 97 + 60 + 0 + 0 + 0 = 666.

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, 144023039716 + ... + 144023040284.

It is an arithmetic number, because the mean of its divisors is an integer number (116684399040).

Almost surely, 2^{81949109760000} is an apocalyptic number.

81949109760000 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 81949109760000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182027662502400).

81949109760000 is an abundant number, since it is smaller than the sum of its proper divisors (282106215244800).

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

81949109760000 is a wasteful number, since it uses less digits than its factorization.

81949109760000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 81949109760000 in words is "eighty-one trillion, nine hundred forty-nine billion, one hundred nine million, seven hundred sixty thousand".