7938679865 has 4 divisors (see below), whose sum is σ = 9526415844. Its totient is φ = 6350943888.

The previous prime is 7938679843. The next prime is 7938679867. The reversal of 7938679865 is 5689768397.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5202448384 + 2736231481 = 72128^2 + 52309^2 .

It is a cyclic number.

It is not a de Polignac number, because 7938679865 - 2¹² = 7938675769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 7938679795 and 7938679804.

It is not an unprimeable number, because it can be changed into a prime (7938679867) 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 3 ways as a sum of consecutive naturals, for example, 793867982 + ... + 793867991.

It is an arithmetic number, because the mean of its divisors is an integer number (2381603961).

Almost surely, 2^7938679865 is an apocalyptic number.

It is an amenable number.

7938679865 is a deficient number, since it is larger than the sum of its proper divisors (1587735979).

7938679865 is a wasteful number, since it uses less digits than its factorization.

7938679865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1587735978.

The product of its digits is 137168640, while the sum is 68.

The square root of 7938679865 is about 89099.2697220353. The cubic root of 7938679865 is about 1994.8768767594.

The spelling of 7938679865 in words is "seven billion, nine hundred thirty-eight million, six hundred seventy-nine thousand, eight hundred sixty-five".