688679 has 2 divisors, whose sum is σ = 688680. Its totient is φ = 688678.

The previous prime is 688669. The next prime is 688697. The reversal of 688679 is 976886.

Together with next prime (688697) 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 688679 - 2⁸ = 688423 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344339 + 344340.

It is an arithmetic number, because the mean of its divisors is an integer number (344340).

2⁶⁸⁸⁶⁷⁹ is an apocalyptic number.

688679 is a deficient number, since it is larger than the sum of its proper divisors (1).

688679 is an equidigital number, since it uses as much as digits as its factorization.

688679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 688679 is about 829.8668567909. The cubic root of 688679 is about 88.3091314576.

The spelling of 688679 in words is "six hundred eighty-eight thousand, six hundred seventy-nine".