211220222021 has 2 divisors, whose sum is σ = 211220222022. Its totient is φ = 211220222020.

The previous prime is 211220221897. The next prime is 211220222023. The reversal of 211220222021 is 120222022112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 205765660996 + 5454561025 = 453614^2 + 73855^2 .

It is a cyclic number.

It is not a de Polignac number, because 211220222021 - 2¹⁰ = 211220220997 is a prime.

It is a super-2 number, since 2×211220222021² (a number of 23 digits) contains 22 as substring.

Together with 211220222023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211220222023) 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, 105610111010 + 105610111011.

It is an arithmetic number, because the mean of its divisors is an integer number (105610111011).

Almost surely, 2^211220222021 is an apocalyptic number.

It is an amenable number.

211220222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

211220222021 is an equidigital number, since it uses as much as digits as its factorization.

211220222021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 211220222021 its reverse (120222022112), we get a palindrome (331442244133).

The spelling of 211220222021 in words is "two hundred eleven billion, two hundred twenty million, two hundred twenty-two thousand, twenty-one".