12001221209 has 4 divisors (see below), whose sum is σ = 12001778304. Its totient is φ = 12000664116.

The previous prime is 12001221187. The next prime is 12001221217. The reversal of 12001221209 is 90212210021.

It is a happy number.

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 12001221209 - 2⁸ = 12001220953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12001221269) 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, 244877 + ... + 289770.

It is an arithmetic number, because the mean of its divisors is an integer number (3000444576).

Almost surely, 2^12001221209 is an apocalyptic number.

It is an amenable number.

12001221209 is a deficient number, since it is larger than the sum of its proper divisors (557095).

12001221209 is an equidigital number, since it uses as much as digits as its factorization.

12001221209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557094.

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 12001221209 in words is "twelve billion, one million, two hundred twenty-one thousand, two hundred nine".