78619315817 has 12 divisors (see below), whose sum is σ = 92707936596. Its totient is φ = 66464858880.

The previous prime is 78619315799. The next prime is 78619315883. The reversal of 78619315817 is 71851391687.

It can be written as a sum of positive squares in 2 ways, for example, as 20455864576 + 58163451241 = 143024^2 + 241171^2 .

It is not a de Polignac number, because 78619315817 - 2²⁴ = 78602538601 is a prime.

It is a Smith number, since the sum of its digits (56) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78619315417) 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 11 ways as a sum of consecutive naturals, for example, 10985984 + ... + 10993137.

It is an arithmetic number, because the mean of its divisors is an integer number (7725661383).

Almost surely, 2^78619315817 is an apocalyptic number.

It is an amenable number.

78619315817 is a deficient number, since it is larger than the sum of its proper divisors (14088620779).

78619315817 is a wasteful number, since it uses less digits than its factorization.

78619315817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21979208 (or 21979201 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 56.

The spelling of 78619315817 in words is "seventy-eight billion, six hundred nineteen million, three hundred fifteen thousand, eight hundred seventeen".