221011212221 has 2 divisors, whose sum is σ = 221011212222. Its totient is φ = 221011212220.

The previous prime is 221011212209. The next prime is 221011212239. The reversal of 221011212221 is 122212110122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189703802500 + 31307409721 = 435550^2 + 176939^2 .

It is a cyclic number.

It is not a de Polignac number, because 221011212221 - 2²⁶ = 220944103357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221011212221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221011212271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110505606110 + 110505606111.

It is an arithmetic number, because the mean of its divisors is an integer number (110505606111).

Almost surely, 2^221011212221 is an apocalyptic number.

It is an amenable number.

221011212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221011212221 is an equidigital number, since it uses as much as digits as its factorization.

221011212221 is an odious number, because the sum of its binary digits is odd.

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

Adding to 221011212221 its reverse (122212110122), we get a palindrome (343223322343).

The spelling of 221011212221 in words is "two hundred twenty-one billion, eleven million, two hundred twelve thousand, two hundred twenty-one".