12728289 has 12 divisors (see below), whose sum is σ = 19742064. Its totient is φ = 7273224.

The previous prime is 12728281. The next prime is 12728293. The reversal of 12728289 is 98282721.

12728289 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12728289 - 2³ = 12728281 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12728281) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43147 + ... + 43440.

It is an arithmetic number, because the mean of its divisors is an integer number (1645172).

Almost surely, 2^12728289 is an apocalyptic number.

It is an amenable number.

12728289 is a deficient number, since it is larger than the sum of its proper divisors (7013775).

12728289 is an equidigital number, since it uses as much as digits as its factorization.

12728289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86604 (or 86597 counting only the distinct ones).

The product of its digits is 32256, while the sum is 39.

The square root of 12728289 is about 3567.6727708690. The cubic root of 12728289 is about 233.4837585587.

The spelling of 12728289 in words is "twelve million, seven hundred twenty-eight thousand, two hundred eighty-nine".