78686 has 4 divisors (see below), whose sum is σ = 118032. Its totient is φ = 39342.

The previous prime is 78653. The next prime is 78691. The reversal of 78686 is 68687.

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

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19670 + ... + 19673.

It is an arithmetic number, because the mean of its divisors is an integer number (29508).

2⁷⁸⁶⁸⁶ is an apocalyptic number.

78686 is a deficient number, since it is larger than the sum of its proper divisors (39346).

78686 is a wasteful number, since it uses less digits than its factorization.

78686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39345.

The product of its digits is 16128, while the sum is 35.

The square root of 78686 is about 280.5102493671. The cubic root of 78686 is about 42.8514796750.

Subtracting from 78686 its reverse (68687), we obtain a palindrome (9999).

The spelling of 78686 in words is "seventy-eight thousand, six hundred eighty-six".