78665635686 has 16 divisors (see below), whose sum is σ = 171634114368. Its totient is φ = 23838071400.

The previous prime is 78665635673. The next prime is 78665635691. The reversal of 78665635686 is 68653656687.

It is a Harshad number since it is a multiple of its sum of digits (66), and also a Moran number because the ratio is a prime number: 1191903571 = 78665635686 / (7 + 8 + 6 + 6 + 5 + 6 + 3 + 5 + 6 + 8 + 6).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 595951720 + ... + 595951851.

It is an arithmetic number, because the mean of its divisors is an integer number (10727132148).

Almost surely, 2^78665635686 is an apocalyptic number.

78665635686 is an abundant number, since it is smaller than the sum of its proper divisors (92968478682).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78665635686 is a wasteful number, since it uses less digits than its factorization.

78665635686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191903587.

The product of its digits is 261273600, while the sum is 66.

The spelling of 78665635686 in words is "seventy-eight billion, six hundred sixty-five million, six hundred thirty-five thousand, six hundred eighty-six".