12644509 has 4 divisors (see below), whose sum is σ = 12651804. Its totient is φ = 12637216.

The previous prime is 12644483. The next prime is 12644561. The reversal of 12644509 is 90544621.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90544621 = 857 ⋅105653.

It can be written as a sum of positive squares in 2 ways, for example, as 3912484 + 8732025 = 1978^2 + 2955^2 .

It is a cyclic number.

It is not a de Polignac number, because 12644509 - 2⁵ = 12644477 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 (12644579) 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, 609 + ... + 5065.

It is an arithmetic number, because the mean of its divisors is an integer number (3162951).

Almost surely, 2^12644509 is an apocalyptic number.

It is an amenable number.

12644509 is a deficient number, since it is larger than the sum of its proper divisors (7295).

12644509 is an equidigital number, since it uses as much as digits as its factorization.

12644509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7294.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 12644509 is about 3555.9118380522. The cubic root of 12644509 is about 232.9703524079.

The spelling of 12644509 in words is "twelve million, six hundred forty-four thousand, five hundred nine".