78686673 has 32 divisors (see below), whose sum is σ = 115944192. Its totient is φ = 47174400.

The previous prime is 78686669. The next prime is 78686719. The reversal of 78686673 is 37668687.

It is not a de Polignac number, because 78686673 - 2² = 78686669 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (78686633) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 434643 + ... + 434823.

It is an arithmetic number, because the mean of its divisors is an integer number (3623256).

Almost surely, 2^78686673 is an apocalyptic number.

It is an amenable number.

78686673 is a deficient number, since it is larger than the sum of its proper divisors (37257519).

78686673 is a wasteful number, since it uses less digits than its factorization.

78686673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425.

The product of its digits is 2032128, while the sum is 51.

The square root of 78686673 is about 8870.5508848098. The cubic root of 78686673 is about 428.5160184395.

It can be divided in two parts, 7868 and 6673, that added together give a palindrome (14541).

The spelling of 78686673 in words is "seventy-eight million, six hundred eighty-six thousand, six hundred seventy-three".