6728678509 has 4 divisors (see below), whose sum is σ = 7689918304. Its totient is φ = 5767438716.

The previous prime is 6728678503. The next prime is 6728678521. The reversal of 6728678509 is 9058768276.

6728678509 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 6728678509 - 2⁵ = 6728678477 is a prime.

It is a super-2 number, since 2×6728678509² = 90550228954956926162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6728678503) 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, 480619887 + ... + 480619900.

It is an arithmetic number, because the mean of its divisors is an integer number (1922479576).

Almost surely, 2^6728678509 is an apocalyptic number.

It is an amenable number.

6728678509 is a deficient number, since it is larger than the sum of its proper divisors (961239795).

6728678509 is an equidigital number, since it uses as much as digits as its factorization.

6728678509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 961239794.

The product of its (nonzero) digits is 10160640, while the sum is 58.

The square root of 6728678509 is about 82028.5225333237. The cubic root of 6728678509 is about 1887.8895948506.

The spelling of 6728678509 in words is "six billion, seven hundred twenty-eight million, six hundred seventy-eight thousand, five hundred nine".