12111220021 has 4 divisors (see below), whose sum is σ = 12111601600. Its totient is φ = 12110838444.

The previous prime is 12111220007. The next prime is 12111220061. The reversal of 12111220021 is 12002211121.

12111220021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 12002211121 = 29 ⋅413869349.

It is a cyclic number.

It is not a de Polignac number, because 12111220021 - 2¹¹ = 12111217973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12111219983 and 12111220010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111220061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138381 + ... + 208258.

It is an arithmetic number, because the mean of its divisors is an integer number (3027900400).

Almost surely, 2^12111220021 is an apocalyptic number.

It is an amenable number.

12111220021 is a deficient number, since it is larger than the sum of its proper divisors (381579).

12111220021 is an equidigital number, since it uses as much as digits as its factorization.

12111220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381578.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 12111220021 its reverse (12002211121), we get a palindrome (24113431142).

The spelling of 12111220021 in words is "twelve billion, one hundred eleven million, two hundred twenty thousand, twenty-one".