81394008192 has 768 divisors, whose sum is σ = 301816368000. Its totient is φ = 21459271680.

The previous prime is 81394008191. The next prime is 81394008271. The reversal of 81394008192 is 29180049318.

81394008192 is a `hidden beast` number, since 81 + 3 + 9 + 400 + 81 + 92 = 666.

It is not an unprimeable number, because it can be changed into a prime (81394008191) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 131918668 + ... + 131919284.

Almost surely, 2^81394008192 is an apocalyptic number.

81394008192 is a gapful number since it is divisible by the number (82) 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 81394008192, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150908184000).

81394008192 is an abundant number, since it is smaller than the sum of its proper divisors (220422359808).

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

81394008192 is a wasteful number, since it uses less digits than its factorization.

81394008192 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714 (or 689 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The spelling of 81394008192 in words is "eighty-one billion, three hundred ninety-four million, eight thousand, one hundred ninety-two".