221211202221 has 6 divisors (see below), whose sum is σ = 319527292110. Its totient is φ = 147474134808.

The previous prime is 221211202187. The next prime is 221211202243. The reversal of 221211202221 is 122202112122.

It is a happy number.

221211202221 is a `hidden beast` number, since 221 + 21 + 1 + 202 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 199575734121 + 21635468100 = 446739^2 + 147090^2 .

It is not a de Polignac number, because 221211202221 - 2¹⁷ = 221211071149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221211202194 and 221211202203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221211202621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12289511226 + ... + 12289511243.

It is an arithmetic number, because the mean of its divisors is an integer number (53254548685).

Almost surely, 2^221211202221 is an apocalyptic number.

It is an amenable number.

221211202221 is a deficient number, since it is larger than the sum of its proper divisors (98316089889).

221211202221 is a wasteful number, since it uses less digits than its factorization.

221211202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24579022475 (or 24579022472 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 221211202221 its reverse (122202112122), we get a palindrome (343413314343).

Subtracting from 221211202221 its reverse (122202112122), we obtain a palindrome (99009090099).

The spelling of 221211202221 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred two thousand, two hundred twenty-one".