6728558861 has 2 divisors, whose sum is σ = 6728558862. Its totient is φ = 6728558860.

The previous prime is 6728558833. The next prime is 6728558899. The reversal of 6728558861 is 1688558276.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5836043236 + 892515625 = 76394^2 + 29875^2 .

It is a cyclic number.

It is not a de Polignac number, because 6728558861 - 2⁶ = 6728558797 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6728558797 and 6728558806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6728558821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3364279430 + 3364279431.

It is an arithmetic number, because the mean of its divisors is an integer number (3364279431).

Almost surely, 2^6728558861 is an apocalyptic number.

It is an amenable number.

6728558861 is a deficient number, since it is larger than the sum of its proper divisors (1).

6728558861 is an equidigital number, since it uses as much as digits as its factorization.

6728558861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6451200, while the sum is 56.

The square root of 6728558861 is about 82027.7932227852. The cubic root of 6728558861 is about 1887.8784047606.

The spelling of 6728558861 in words is "six billion, seven hundred twenty-eight million, five hundred fifty-eight thousand, eight hundred sixty-one".