6668657 has 4 divisors (see below), whose sum is σ = 6689136. Its totient is φ = 6648180.

The previous prime is 6668617. The next prime is 6668659. The reversal of 6668657 is 7568666.

6668657 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6668657 - 2¹⁴ = 6652273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6668659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9743 + ... + 10404.

It is an arithmetic number, because the mean of its divisors is an integer number (1672284).

Almost surely, 2^6668657 is an apocalyptic number.

It is an amenable number.

6668657 is a deficient number, since it is larger than the sum of its proper divisors (20479).

6668657 is a wasteful number, since it uses less digits than its factorization.

6668657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20478.

The product of its digits is 362880, while the sum is 44.

The square root of 6668657 is about 2582.3742951013. The cubic root of 6668657 is about 188.2259336664.

Subtracting 6668657 from its reverse (7568666), we obtain a palindrome (900009).

The spelling of 6668657 in words is "six million, six hundred sixty-eight thousand, six hundred fifty-seven".