2021210221 has 2 divisors, whose sum is σ = 2021210222. Its totient is φ = 2021210220.

The previous prime is 2021210209. The next prime is 2021210237. The reversal of 2021210221 is 1220121202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1837065321 + 184144900 = 42861^2 + 13570^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021210221 - 2¹¹ = 2021208173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021210201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010605110 + 1010605111.

It is an arithmetic number, because the mean of its divisors is an integer number (1010605111).

Almost surely, 2^2021210221 is an apocalyptic number.

It is an amenable number.

2021210221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021210221 is an equidigital number, since it uses as much as digits as its factorization.

2021210221 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2021210221 is about 44957.8716244441. The cubic root of 2021210221 is about 1264.3592647404.

Adding to 2021210221 its reverse (1220121202), we get a palindrome (3241331423).

The spelling of 2021210221 in words is "two billion, twenty-one million, two hundred ten thousand, two hundred twenty-one".