12138439 has 4 divisors (see below), whose sum is σ = 12150424. Its totient is φ = 12126456.

The previous prime is 12138421. The next prime is 12138449. The reversal of 12138439 is 93483121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93483121 = 2953 ⋅31657.

It is a cyclic number.

It is not a de Polignac number, because 12138439 - 2⁷ = 12138311 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12138439.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12138409) 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, 4317 + ... + 6550.

It is an arithmetic number, because the mean of its divisors is an integer number (3037606).

Almost surely, 2^12138439 is an apocalyptic number.

12138439 is a deficient number, since it is larger than the sum of its proper divisors (11985).

12138439 is a wasteful number, since it uses less digits than its factorization.

12138439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11984.

The product of its digits is 5184, while the sum is 31.

The square root of 12138439 is about 3484.0262628172. The cubic root of 12138439 is about 229.8198905018.

The spelling of 12138439 in words is "twelve million, one hundred thirty-eight thousand, four hundred thirty-nine".