12439309 has 4 divisors (see below), whose sum is σ = 12489120. Its totient is φ = 12389500.

The previous prime is 12439283. The next prime is 12439321. The reversal of 12439309 is 90393421.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12439309 - 2¹¹ = 12437261 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 (12439369) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24529 + ... + 25030.

It is an arithmetic number, because the mean of its divisors is an integer number (3122280).

Almost surely, 2^12439309 is an apocalyptic number.

It is an amenable number.

12439309 is a deficient number, since it is larger than the sum of its proper divisors (49811).

12439309 is an equidigital number, since it uses as much as digits as its factorization.

12439309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49810.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 12439309 is about 3526.9404588113. The cubic root of 12439309 is about 231.7032285916.

The spelling of 12439309 in words is "twelve million, four hundred thirty-nine thousand, three hundred nine".