78634646579 has 4 divisors (see below), whose sum is σ = 78667182984. Its totient is φ = 78602110176.

The previous prime is 78634646501. The next prime is 78634646611. The reversal of 78634646579 is 97564643687.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78634646579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78634648579) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16264577 + ... + 16269410.

It is an arithmetic number, because the mean of its divisors is an integer number (19666795746).

Almost surely, 2^78634646579 is an apocalyptic number.

78634646579 is a deficient number, since it is larger than the sum of its proper divisors (32536405).

78634646579 is a wasteful number, since it uses less digits than its factorization.

78634646579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32536404.

The product of its digits is 182891520, while the sum is 65.

The spelling of 78634646579 in words is "seventy-eight billion, six hundred thirty-four million, six hundred forty-six thousand, five hundred seventy-nine".