81717023181578 has 8 divisors (see below), whose sum is σ = 123540696463872. Its totient is φ = 40536791026956.

The previous prime is 81717023181523. The next prime is 81717023181581. The reversal of 81717023181578 is 87518132071718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 160860281600 + ... + 160860282107.

It is an arithmetic number, because the mean of its divisors is an integer number (15442587057984).

Almost surely, 2^{81717023181578} is an apocalyptic number.

81717023181578 is a deficient number, since it is larger than the sum of its proper divisors (41823673282294).

81717023181578 is a wasteful number, since it uses less digits than its factorization.

81717023181578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321720563836.

The product of its (nonzero) digits is 5268480, while the sum is 59.

The spelling of 81717023181578 in words is "eighty-one trillion, seven hundred seventeen billion, twenty-three million, one hundred eighty-one thousand, five hundred seventy-eight".