668685689 has 8 divisors (see below), whose sum is σ = 764431680. Its totient is φ = 572994576.

The previous prime is 668685673. The next prime is 668685697. The reversal of 668685689 is 986586866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 668685689 - 2⁴ = 668685673 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 (668685659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16982 + ... + 40320.

It is an arithmetic number, because the mean of its divisors is an integer number (95553960).

Almost surely, 2^668685689 is an apocalyptic number.

It is an amenable number.

668685689 is a deficient number, since it is larger than the sum of its proper divisors (95745991).

668685689 is a wasteful number, since it uses less digits than its factorization.

668685689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27439.

The product of its digits is 29859840, while the sum is 62.

The square root of 668685689 is about 25858.9576162691. The cubic root of 668685689 is about 874.4614651883.

The spelling of 668685689 in words is "six hundred sixty-eight million, six hundred eighty-five thousand, six hundred eighty-nine".