7728689 has 2 divisors, whose sum is σ = 7728690. Its totient is φ = 7728688.

The previous prime is 7728673. The next prime is 7728697. The reversal of 7728689 is 9868277.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7728400 + 289 = 2780^2 + 17^2 .

It is a cyclic number.

It is not a de Polignac number, because 7728689 - 2⁴ = 7728673 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (7728389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3864344 + 3864345.

It is an arithmetic number, because the mean of its divisors is an integer number (3864345).

Almost surely, 2^7728689 is an apocalyptic number.

It is an amenable number.

7728689 is a deficient number, since it is larger than the sum of its proper divisors (1).

7728689 is an equidigital number, since it uses as much as digits as its factorization.

7728689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 47.

The square root of 7728689 is about 2780.0519779313. The cubic root of 7728689 is about 197.7130233685.

The spelling of 7728689 in words is "seven million, seven hundred twenty-eight thousand, six hundred eighty-nine".