12021000209 has 4 divisors (see below), whose sum is σ = 12543652416. Its totient is φ = 11498348004.

The previous prime is 12021000191. The next prime is 12021000353. The reversal of 12021000209 is 90200012021.

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 12021000209 - 2²⁸ = 11752564753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12021003209) 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, 261326069 + ... + 261326114.

It is an arithmetic number, because the mean of its divisors is an integer number (3135913104).

Almost surely, 2^12021000209 is an apocalyptic number.

It is an amenable number.

12021000209 is a deficient number, since it is larger than the sum of its proper divisors (522652207).

12021000209 is an equidigital number, since it uses as much as digits as its factorization.

12021000209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522652206.

The product of its (nonzero) digits is 72, while the sum is 17.

The spelling of 12021000209 in words is "twelve billion, twenty-one million, two hundred nine", and thus it is an aban number.