221021222220221 has 2 divisors, whose sum is σ = 221021222220222. Its totient is φ = 221021222220220.

The previous prime is 221021222220157. The next prime is 221021222220307. The reversal of 221021222220221 is 122022222120122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127331792971321 + 93689429248900 = 11284139^2 + 9679330^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021222220221 - 2⁶ = 221021222220157 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221021222226221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510611110110 + 110510611110111.

It is an arithmetic number, because the mean of its divisors is an integer number (110510611110111).

Almost surely, 2^{221021222220221} is an apocalyptic number.

It is an amenable number.

221021222220221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021222220221 is an equidigital number, since it uses as much as digits as its factorization.

221021222220221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 221021222220221 its reverse (122022222120122), we get a palindrome (343043444340343).

The spelling of 221021222220221 in words is "two hundred twenty-one trillion, twenty-one billion, two hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".