12638709 has 12 divisors (see below), whose sum is σ = 18506956. Its totient is φ = 8309952.

The previous prime is 12638699. The next prime is 12638741. The reversal of 12638709 is 90783621.

12638709 is a `hidden beast` number, since 12 + 638 + 7 + 0 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4100625 + 8538084 = 2025^2 + 2922^2 .

It is not a de Polignac number, because 12638709 - 2⁷ = 12638581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12638779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8962 + ... + 10275.

Almost surely, 2^12638709 is an apocalyptic number.

It is an amenable number.

12638709 is a deficient number, since it is larger than the sum of its proper divisors (5868247).

12638709 is a wasteful number, since it uses less digits than its factorization.

12638709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19316 (or 19313 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 12638709 is about 3555.0962012300. The cubic root of 12638709 is about 232.9347260160.

The spelling of 12638709 in words is "twelve million, six hundred thirty-eight thousand, seven hundred nine".