12220021021 has 4 divisors (see below), whose sum is σ = 13160022652. Its totient is φ = 11280019392.

The previous prime is 12220021001. The next prime is 12220021061. The reversal of 12220021021 is 12012002221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12012002221 = 107 ⋅112261703.

It can be written as a sum of positive squares in 2 ways, for example, as 4863528121 + 7356492900 = 69739^2 + 85770^2 .

It is a cyclic number.

It is not a de Polignac number, because 12220021021 - 2²⁷ = 12085803293 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 940001617 = 12220021021 / (1 + 2 + 2 + 2 + 0 + 0 + 2 + 1 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12220020992 and 12220021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12220021001) 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, 470000796 + ... + 470000821.

It is an arithmetic number, because the mean of its divisors is an integer number (3290005663).

Almost surely, 2^12220021021 is an apocalyptic number.

It is an amenable number.

12220021021 is a deficient number, since it is larger than the sum of its proper divisors (940001631).

12220021021 is an equidigital number, since it uses as much as digits as its factorization.

12220021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 940001630.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 12220021021 its reverse (12012002221), we get a palindrome (24232023242).

The spelling of 12220021021 in words is "twelve billion, two hundred twenty million, twenty-one thousand, twenty-one".