668591009 has 8 divisors (see below), whose sum is σ = 680862240. Its totient is φ = 656351200.

The previous prime is 668591003. The next prime is 668591029. The reversal of 668591009 is 900195866.

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

It is a cyclic number.

It is not a de Polignac number, because 668591009 - 2¹² = 668586913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668591003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37454 + ... + 52344.

It is an arithmetic number, because the mean of its divisors is an integer number (85107780).

Almost surely, 2^668591009 is an apocalyptic number.

It is an amenable number.

668591009 is a deficient number, since it is larger than the sum of its proper divisors (12271231).

668591009 is a wasteful number, since it uses less digits than its factorization.

668591009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15711.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 668591009 is about 25857.1268512184. The cubic root of 668591009 is about 874.4201912281.

The spelling of 668591009 in words is "six hundred sixty-eight million, five hundred ninety-one thousand, nine".