12005209 has 4 divisors (see below), whose sum is σ = 12055680. Its totient is φ = 11954740.

The previous prime is 12005171. The next prime is 12005219. The reversal of 12005209 is 90250021.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90250021 = 31 ⋅2911291.

It is a cyclic number.

It is not a de Polignac number, because 12005209 - 2¹¹ = 12003161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12005219) 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, 24877 + ... + 25354.

It is an arithmetic number, because the mean of its divisors is an integer number (3013920).

Almost surely, 2^12005209 is an apocalyptic number.

It is an amenable number.

12005209 is a deficient number, since it is larger than the sum of its proper divisors (50471).

12005209 is an equidigital number, since it uses as much as digits as its factorization.

12005209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50470.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 12005209 is about 3464.8533879516. The cubic root of 12005209 is about 228.9759704768.

The spelling of 12005209 in words is "twelve million, five thousand, two hundred nine".