210221021100221 has 2 divisors, whose sum is σ = 210221021100222. Its totient is φ = 210221021100220.

The previous prime is 210221021100191. The next prime is 210221021100239. The reversal of 210221021100221 is 122001120122012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206756043612196 + 3464977488025 = 14379014^2 + 1861445^2 .

It is a cyclic number.

It is not a de Polignac number, because 210221021100221 - 2¹⁸ = 210221020838077 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 210221021100221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210221021100121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105110510550110 + 105110510550111.

It is an arithmetic number, because the mean of its divisors is an integer number (105110510550111).

Almost surely, 2^{210221021100221} is an apocalyptic number.

It is an amenable number.

210221021100221 is a deficient number, since it is larger than the sum of its proper divisors (1).

210221021100221 is an equidigital number, since it uses as much as digits as its factorization.

210221021100221 is an evil number, because the sum of its binary digits is even.

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

Adding to 210221021100221 its reverse (122001120122012), we get a palindrome (332222141222233).

The spelling of 210221021100221 in words is "two hundred ten trillion, two hundred twenty-one billion, twenty-one million, one hundred thousand, two hundred twenty-one".