12039809 has 4 divisors (see below), whose sum is σ = 12091716. Its totient is φ = 11987904.

The previous prime is 12039803. The next prime is 12039821. The reversal of 12039809 is 90893021.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90893021 = 2137 ⋅42533.

It can be written as a sum of positive squares in 2 ways, for example, as 8151025 + 3888784 = 2855^2 + 1972^2 .

It is a cyclic number.

It is not a de Polignac number, because 12039809 - 2⁴ = 12039793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12039803) 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 3 ways as a sum of consecutive naturals, for example, 25604 + ... + 26069.

It is an arithmetic number, because the mean of its divisors is an integer number (3022929).

Almost surely, 2^12039809 is an apocalyptic number.

It is an amenable number.

12039809 is a deficient number, since it is larger than the sum of its proper divisors (51907).

12039809 is an equidigital number, since it uses as much as digits as its factorization.

12039809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51906.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 12039809 is about 3469.8427918279. The cubic root of 12039809 is about 229.1957353466.

The spelling of 12039809 in words is "twelve million, thirty-nine thousand, eight hundred nine".