2021210211221 has 2 divisors, whose sum is σ = 2021210211222. Its totient is φ = 2021210211220.

The previous prime is 2021210211211. The next prime is 2021210211239. The reversal of 2021210211221 is 1221120121202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1576307871121 + 444902340100 = 1255511^2 + 667010^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021210211221 - 2¹⁴ = 2021210194837 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2021210211221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021210211211) 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 as a sum of consecutive naturals, namely, 1010605105610 + 1010605105611.

It is an arithmetic number, because the mean of its divisors is an integer number (1010605105611).

Almost surely, 2^{2021210211221} is an apocalyptic number.

It is an amenable number.

2021210211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021210211221 is an equidigital number, since it uses as much as digits as its factorization.

2021210211221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2021210211221 its reverse (1221120121202), we get a palindrome (3242330332423).

The spelling of 2021210211221 in words is "two trillion, twenty-one billion, two hundred ten million, two hundred eleven thousand, two hundred twenty-one".