81168783239808 has 1024 divisors, whose sum is σ = 283521594470400. Its totient is φ = 22581470822400.

The previous prime is 81168783239741. The next prime is 81168783239839. The reversal of 81168783239808 is 80893238786118.

81168783239808 is a `hidden beast` number, since 8 + 1 + 168 + 78 + 3 + 2 + 398 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 28651175160 + ... + 28651177992.

It is an arithmetic number, because the mean of its divisors is an integer number (276876557100).

Almost surely, 2^{81168783239808} is an apocalyptic number.

81168783239808 is a gapful number since it is divisible by the number (88) 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 81168783239808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141760797235200).

81168783239808 is an abundant number, since it is smaller than the sum of its proper divisors (202352811230592).

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

81168783239808 is a wasteful number, since it uses less digits than its factorization.

81168783239808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3958 (or 3940 counting only the distinct ones).

The product of its (nonzero) digits is 222953472, while the sum is 72.

The spelling of 81168783239808 in words is "eighty-one trillion, one hundred sixty-eight billion, seven hundred eighty-three million, two hundred thirty-nine thousand, eight hundred eight".