12001211209 has 4 divisors (see below), whose sum is σ = 12924381316. Its totient is φ = 11078041104.

The previous prime is 12001211207. The next prime is 12001211227. The reversal of 12001211209 is 90211210021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90211210021 = 131 ⋅688635191.

It can be written as a sum of positive squares in 2 ways, for example, as 6017415184 + 5983796025 = 77572^2 + 77355^2 .

It is not a de Polignac number, because 12001211209 - 2¹ = 12001211207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12001211203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 461585034 + ... + 461585059.

It is an arithmetic number, because the mean of its divisors is an integer number (3231095329).

Almost surely, 2^12001211209 is an apocalyptic number.

It is an amenable number.

12001211209 is a deficient number, since it is larger than the sum of its proper divisors (923170107).

12001211209 is an equidigital number, since it uses as much as digits as its factorization.

12001211209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923170106.

The product of its (nonzero) digits is 72, while the sum is 19.

The spelling of 12001211209 in words is "twelve billion, one million, two hundred eleven thousand, two hundred nine".