686405028679 has 2 divisors, whose sum is σ = 686405028680. Its totient is φ = 686405028678.

The previous prime is 686405028667. The next prime is 686405028697. The reversal of 686405028679 is 976820504686.

Together with next prime (686405028697) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 686405028679 - 2³³ = 677815094087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686405028619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343202514339 + 343202514340.

It is an arithmetic number, because the mean of its divisors is an integer number (343202514340).

Almost surely, 2^686405028679 is an apocalyptic number.

686405028679 is a deficient number, since it is larger than the sum of its proper divisors (1).

686405028679 is an equidigital number, since it uses as much as digits as its factorization.

686405028679 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34836480, while the sum is 61.

The spelling of 686405028679 in words is "six hundred eighty-six billion, four hundred five million, twenty-eight thousand, six hundred seventy-nine".