12721709 has 32 divisors (see below), whose sum is σ = 17418240. Its totient is φ = 8971200.

The previous prime is 12721703. The next prime is 12721711. The reversal of 12721709 is 90712721.

It is not a de Polignac number, because 12721709 - 2⁴ = 12721693 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12721703) 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 31 ways as a sum of consecutive naturals, for example, 70982 + ... + 71160.

It is an arithmetic number, because the mean of its divisors is an integer number (544320).

Almost surely, 2^12721709 is an apocalyptic number.

It is an amenable number.

12721709 is a deficient number, since it is larger than the sum of its proper divisors (4696531).

12721709 is a wasteful number, since it uses less digits than its factorization.

12721709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 12721709 is about 3566.7504818812. The cubic root of 12721709 is about 233.4435178019.

The spelling of 12721709 in words is "twelve million, seven hundred twenty-one thousand, seven hundred nine".