78644044687 has 4 divisors (see below), whose sum is σ = 84693586600. Its totient is φ = 72594502776.

The previous prime is 78644044681. The next prime is 78644044741.

It is a happy number.

78644044687 is nontrivially palindromic in base 10.

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

It is a cyclic number.

It is not a de Polignac number, because 78644044687 - 2³ = 78644044679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78644044681) 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, 3024770937 + ... + 3024770962.

It is an arithmetic number, because the mean of its divisors is an integer number (21173396650).

Almost surely, 2^78644044687 is an apocalyptic number.

78644044687 is a deficient number, since it is larger than the sum of its proper divisors (6049541913).

78644044687 is a wasteful number, since it uses less digits than its factorization.

78644044687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6049541912.

The product of its (nonzero) digits is 28901376, while the sum is 58.

The spelling of 78644044687 in words is "seventy-eight billion, six hundred forty-four million, forty-four thousand, six hundred eighty-seven".