12728709 has 24 divisors (see below), whose sum is σ = 21740160. Its totient is φ = 7021728.

The previous prime is 12728707. The next prime is 12728711. The reversal of 12728709 is 90782721.

It is an interprime number because it is at equal distance from previous prime (12728707) and next prime (12728711).

It is not a de Polignac number, because 12728709 - 2¹ = 12728707 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12728707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1657 + ... + 5310.

It is an arithmetic number, because the mean of its divisors is an integer number (905840).

Almost surely, 2^12728709 is an apocalyptic number.

It is an amenable number.

12728709 is a deficient number, since it is larger than the sum of its proper divisors (9011451).

12728709 is a wasteful number, since it uses less digits than its factorization.

12728709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7009 (or 7006 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 12728709 is about 3567.7316322840. The cubic root of 12728709 is about 233.4863266467.

The spelling of 12728709 in words is "twelve million, seven hundred twenty-eight thousand, seven hundred nine".