6666789 has 4 divisors (see below), whose sum is σ = 8889056. Its totient is φ = 4444524.

The previous prime is 6666769. The next prime is 6666791. The reversal of 6666789 is 9876666.

It is a happy number.

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 6666789 - 2¹⁹ = 6142501 is a prime.

It is a D-number.

It is a Duffinian number.

6666789 is a lucky number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111129 + ... + 1111134.

It is an arithmetic number, because the mean of its divisors is an integer number (2222264).

Almost surely, 2^6666789 is an apocalyptic number.

It is an amenable number.

6666789 is a deficient number, since it is larger than the sum of its proper divisors (2222267).

6666789 is a wasteful number, since it uses less digits than its factorization.

6666789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2222266.

The product of its digits is 653184, while the sum is 48.

The square root of 6666789 is about 2582.0125871111. The cubic root of 6666789 is about 188.2083569699.

The spelling of 6666789 in words is "six million, six hundred sixty-six thousand, seven hundred eighty-nine".