12220121021 has 4 divisors (see below), whose sum is σ = 12220570044. Its totient is φ = 12219672000.

The previous prime is 12220120973. The next prime is 12220121041. The reversal of 12220121021 is 12012102221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1587624025 + 10632496996 = 39845^2 + 103114^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12220121021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12220120987 and 12220121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12220121041) 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, 180860 + ... + 239061.

It is an arithmetic number, because the mean of its divisors is an integer number (3055142511).

Almost surely, 2^12220121021 is an apocalyptic number.

It is an amenable number.

12220121021 is a deficient number, since it is larger than the sum of its proper divisors (449023).

12220121021 is an equidigital number, since it uses as much as digits as its factorization.

12220121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449022.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 12220121021 its reverse (12012102221), we get a palindrome (24232223242).

The spelling of 12220121021 in words is "twelve billion, two hundred twenty million, one hundred twenty-one thousand, twenty-one".