211210210001221 has 2 divisors, whose sum is σ = 211210210001222. Its totient is φ = 211210210001220.

The previous prime is 211210210001201. The next prime is 211210210001237. The reversal of 211210210001221 is 122100012012112.

It is an a-pointer prime, because the next prime (211210210001237) can be obtained adding 211210210001221 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 202635936750625 + 8574273250596 = 14235025^2 + 2928186^2 .

It is a cyclic number.

It is not a de Polignac number, because 211210210001221 - 2⁴⁵ = 176025837912389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211210210001195 and 211210210001204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211210210001201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105605105000610 + 105605105000611.

It is an arithmetic number, because the mean of its divisors is an integer number (105605105000611).

Almost surely, 2^{211210210001221} is an apocalyptic number.

It is an amenable number.

211210210001221 is a deficient number, since it is larger than the sum of its proper divisors (1).

211210210001221 is an equidigital number, since it uses as much as digits as its factorization.

211210210001221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 211210210001221 its reverse (122100012012112), we get a palindrome (333310222013333).

The spelling of 211210210001221 in words is "two hundred eleven trillion, two hundred ten billion, two hundred ten million, one thousand, two hundred twenty-one".