688697 has 2 divisors, whose sum is σ = 688698. Its totient is φ = 688696.

The previous prime is 688679. The next prime is 688717. The reversal of 688697 is 796886.

Together with previous prime (688679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 657721 + 30976 = 811^2 + 176^2 .

It is a cyclic number.

It is not a de Polignac number, because 688697 - 2¹⁸ = 426553 is a prime.

It is not a weakly prime, because it can be changed into another prime (688627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344348 + 344349.

It is an arithmetic number, because the mean of its divisors is an integer number (344349).

2⁶⁸⁸⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

688697 is a deficient number, since it is larger than the sum of its proper divisors (1).

688697 is an equidigital number, since it uses as much as digits as its factorization.

688697 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 688697 is about 829.8777018332. The cubic root of 688697 is about 88.3099008293.

The spelling of 688697 in words is "six hundred eighty-eight thousand, six hundred ninety-seven".