12011220021 has 4 divisors (see below), whose sum is σ = 16014960032. Its totient is φ = 8007480012.

The previous prime is 12011220019. The next prime is 12011220073. The reversal of 12011220021 is 12002211021.

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 12011220021 - 2¹ = 12011220019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12011219979 and 12011220006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12011220421) 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, 2001870001 + ... + 2001870006.

It is an arithmetic number, because the mean of its divisors is an integer number (4003740008).

Almost surely, 2^12011220021 is an apocalyptic number.

It is an amenable number.

12011220021 is a deficient number, since it is larger than the sum of its proper divisors (4003740011).

12011220021 is an equidigital number, since it uses as much as digits as its factorization.

12011220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4003740010.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 12011220021 its reverse (12002211021), we get a palindrome (24013431042).

The spelling of 12011220021 in words is "twelve billion, eleven million, two hundred twenty thousand, twenty-one".