668247209 has 16 divisors (see below), whose sum is σ = 772895616. Its totient is φ = 565920000.

The previous prime is 668247127. The next prime is 668247263. The reversal of 668247209 is 902742866.

668247209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 668247209 - 2²⁰ = 667198633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 668247209.

It is not an unprimeable number, because it can be changed into a prime (668247289) 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, 555809 + ... + 557009.

It is an arithmetic number, because the mean of its divisors is an integer number (48305976).

Almost surely, 2^668247209 is an apocalyptic number.

It is an amenable number.

668247209 is a deficient number, since it is larger than the sum of its proper divisors (104648407).

668247209 is a wasteful number, since it uses less digits than its factorization.

668247209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2096.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 668247209 is about 25850.4779259495. The cubic root of 668247209 is about 874.2702853309.

The spelling of 668247209 in words is "six hundred sixty-eight million, two hundred forty-seven thousand, two hundred nine".