6728405909 has 2 divisors, whose sum is σ = 6728405910. Its totient is φ = 6728405908.

The previous prime is 6728405903. The next prime is 6728405917. The reversal of 6728405909 is 9095048276.

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., 6649587025 + 78818884 = 81545^2 + 8878^2 .

It is a cyclic number.

It is not a de Polignac number, because 6728405909 - 2²⁰ = 6727357333 is a prime.

It is a super-2 number, since 2×6728405909² = 90542892152532232562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6728405903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3364202954 + 3364202955.

It is an arithmetic number, because the mean of its divisors is an integer number (3364202955).

Almost surely, 2^6728405909 is an apocalyptic number.

It is an amenable number.

6728405909 is a deficient number, since it is larger than the sum of its proper divisors (1).

6728405909 is an equidigital number, since it uses as much as digits as its factorization.

6728405909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The square root of 6728405909 is about 82026.8608993420. The cubic root of 6728405909 is about 1887.8640997179.

The spelling of 6728405909 in words is "six billion, seven hundred twenty-eight million, four hundred five thousand, nine hundred nine".