78639039779 has 8 divisors (see below), whose sum is σ = 80719312320. Its totient is φ = 76583680936.

The previous prime is 78639039763. The next prime is 78639039823. The reversal of 78639039779 is 97793093687.

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 78639039779 - 2⁴ = 78639039763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78639039379) 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, 6222029 + ... + 6234654.

It is an arithmetic number, because the mean of its divisors is an integer number (10089914040).

Almost surely, 2^78639039779 is an apocalyptic number.

78639039779 is a deficient number, since it is larger than the sum of its proper divisors (2080272541).

78639039779 is a wasteful number, since it uses less digits than its factorization.

78639039779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12456849.

The product of its (nonzero) digits is 108020304, while the sum is 68.

The spelling of 78639039779 in words is "seventy-eight billion, six hundred thirty-nine million, thirty-nine thousand, seven hundred seventy-nine".