12728665 has 8 divisors (see below), whose sum is σ = 16173000. Its totient is φ = 9583872.

The previous prime is 12728663. The next prime is 12728707. The reversal of 12728665 is 56682721.

It is a happy number.

12728665 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 147456 + 12581209 = 384^2 + 3547^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12728665 - 2¹ = 12728663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12728663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74790 + ... + 74959.

It is an arithmetic number, because the mean of its divisors is an integer number (2021625).

Almost surely, 2^12728665 is an apocalyptic number.

It is an amenable number.

12728665 is a deficient number, since it is larger than the sum of its proper divisors (3444335).

12728665 is a wasteful number, since it uses less digits than its factorization.

12728665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149771.

The product of its digits is 40320, while the sum is 37.

The square root of 12728665 is about 3567.7254658956. The cubic root of 12728665 is about 233.4860576115.

The spelling of 12728665 in words is "twelve million, seven hundred twenty-eight thousand, six hundred sixty-five".