17978392817 has 8 divisors (see below), whose sum is σ = 22414619712. Its totient is φ = 14009137200.

The previous prime is 17978392793. The next prime is 17978392877. The reversal of 17978392817 is 71829387971.

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

It is a cyclic number.

It is not a de Polignac number, because 17978392817 - 2⁶ = 17978392753 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 17978392817.

It is not an unprimeable number, because it can be changed into a prime (17978392877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 116742734 + ... + 116742887.

It is an arithmetic number, because the mean of its divisors is an integer number (2801827464).

Almost surely, 2^17978392817 is an apocalyptic number.

It is an amenable number.

17978392817 is a deficient number, since it is larger than the sum of its proper divisors (4436226895).

17978392817 is a wasteful number, since it uses less digits than its factorization.

17978392817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233485639.

The product of its digits is 10668672, while the sum is 62.

The spelling of 17978392817 in words is "seventeen billion, nine hundred seventy-eight million, three hundred ninety-two thousand, eight hundred seventeen".