688705689 has 16 divisors (see below), whose sum is σ = 1059648512. Its totient is φ = 389724048.

The previous prime is 688705631. The next prime is 688705727. The reversal of 688705689 is 986507886.

It is not a de Polignac number, because 688705689 - 2⁹ = 688705177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (688700689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 157039 + ... + 161364.

It is an arithmetic number, because the mean of its divisors is an integer number (66228032).

Almost surely, 2^688705689 is an apocalyptic number.

It is an amenable number.

688705689 is a deficient number, since it is larger than the sum of its proper divisors (370942823).

688705689 is a wasteful number, since it uses less digits than its factorization.

688705689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318516.

The product of its (nonzero) digits is 5806080, while the sum is 57.

The square root of 688705689 is about 26243.2027199425. The cubic root of 688705689 is about 883.1027221739.

The spelling of 688705689 in words is "six hundred eighty-eight million, seven hundred five thousand, six hundred eighty-nine".