12012111021 has 4 divisors (see below), whose sum is σ = 16016148032. Its totient is φ = 8008074012.

The previous prime is 12012111019. The next prime is 12012111047. The reversal of 12012111021 is 12011121021.

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 not a de Polignac number, because 12012111021 - 2¹ = 12012111019 is a prime.

It is a super-2 number, since 2×12012111021² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12012110988 and 12012111006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12012111061) 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, 2002018501 + ... + 2002018506.

It is an arithmetic number, because the mean of its divisors is an integer number (4004037008).

Almost surely, 2^12012111021 is an apocalyptic number.

It is an amenable number.

12012111021 is a deficient number, since it is larger than the sum of its proper divisors (4004037011).

12012111021 is an equidigital number, since it uses as much as digits as its factorization.

12012111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4004037010.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 12012111021 its reverse (12011121021), we get a palindrome (24023232042).

The spelling of 12012111021 in words is "twelve billion, twelve million, one hundred eleven thousand, twenty-one".