6666609 has 4 divisors (see below), whose sum is σ = 8888816. Its totient is φ = 4444404.

The previous prime is 6666599. The next prime is 6666613. The reversal of 6666609 is 9066666.

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 not a de Polignac number, because 6666609 - 2⁴ = 6666593 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6666679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111099 + ... + 1111104.

It is an arithmetic number, because the mean of its divisors is an integer number (2222204).

Almost surely, 2^6666609 is an apocalyptic number.

It is an amenable number.

6666609 is a deficient number, since it is larger than the sum of its proper divisors (2222207).

6666609 is a wasteful number, since it uses less digits than its factorization.

6666609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2222206.

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 6666609 is about 2581.9777303455. The cubic root of 6666609 is about 188.2066631105.

The spelling of 6666609 in words is "six million, six hundred sixty-six thousand, six hundred nine".