12644399 has 4 divisors (see below), whose sum is σ = 12722136. Its totient is φ = 12566664.

The previous prime is 12644393. The next prime is 12644459. The reversal of 12644399 is 99344621.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12644399 - 2²⁰ = 11595823 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 (12644393) 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 3 ways as a sum of consecutive naturals, for example, 38624 + ... + 38949.

It is an arithmetic number, because the mean of its divisors is an integer number (3180534).

Almost surely, 2^12644399 is an apocalyptic number.

12644399 is a deficient number, since it is larger than the sum of its proper divisors (77737).

12644399 is an equidigital number, since it uses as much as digits as its factorization.

12644399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77736.

The product of its digits is 46656, while the sum is 38.

The square root of 12644399 is about 3555.8963708185. The cubic root of 12644399 is about 232.9696768363.

The spelling of 12644399 in words is "twelve million, six hundred forty-four thousand, three hundred ninety-nine".