81366758592 has 112 divisors (see below), whose sum is σ = 246748035840. Its totient is φ = 23180516352.

The previous prime is 81366758569. The next prime is 81366758593. The reversal of 81366758592 is 29585766318.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (81366758593) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 379134 + ... + 553602.

Almost surely, 2^81366758592 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81366758592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123374017920).

81366758592 is an abundant number, since it is smaller than the sum of its proper divisors (165381277248).

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

81366758592 is a wasteful number, since it uses less digits than its factorization.

81366758592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174838 (or 174828 counting only the distinct ones).

The product of its digits is 21772800, while the sum is 60.

The spelling of 81366758592 in words is "eighty-one billion, three hundred sixty-six million, seven hundred fifty-eight thousand, five hundred ninety-two".