686838679 has 4 divisors (see below), whose sum is σ = 686924440. Its totient is φ = 686752920.

The previous prime is 686838653. The next prime is 686838703. The reversal of 686838679 is 976838686.

686838679 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 976838686 = 2 ⋅488419343.

It is a cyclic number.

It is not a de Polignac number, because 686838679 - 2²⁹ = 149967767 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 (686838629) 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, 29469 + ... + 47350.

It is an arithmetic number, because the mean of its divisors is an integer number (171731110).

Almost surely, 2^686838679 is an apocalyptic number.

686838679 is a deficient number, since it is larger than the sum of its proper divisors (85761).

686838679 is an equidigital number, since it uses as much as digits as its factorization.

686838679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85760.

The product of its digits is 20901888, while the sum is 61.

The square root of 686838679 is about 26207.6072734617. The cubic root of 686838679 is about 882.3039998935.

The spelling of 686838679 in words is "six hundred eighty-six million, eight hundred thirty-eight thousand, six hundred seventy-nine".