221222120121 has 24 divisors (see below), whose sum is σ = 322796130696. Its totient is φ = 145980806400.

The previous prime is 221222120089. The next prime is 221222120129. The reversal of 221222120121 is 121021222122.

It is a happy number.

221222120121 is a `hidden beast` number, since 221 + 2 + 221 + 201 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 11462700096 + 209759420025 = 107064^2 + 457995^2 .

It is not a de Polignac number, because 221222120121 - 2⁵ = 221222120089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221222120094 and 221222120103.

It is not an unprimeable number, because it can be changed into a prime (221222120129) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3452451 + ... + 3515943.

It is an arithmetic number, because the mean of its divisors is an integer number (13449838779).

Almost surely, 2^221222120121 is an apocalyptic number.

It is an amenable number.

221222120121 is a deficient number, since it is larger than the sum of its proper divisors (101574010575).

221222120121 is a wasteful number, since it uses less digits than its factorization.

221222120121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67433 (or 67430 counting only the distinct ones).

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

Adding to 221222120121 its reverse (121021222122), we get a palindrome (342243342243).

The spelling of 221222120121 in words is "two hundred twenty-one billion, two hundred twenty-two million, one hundred twenty thousand, one hundred twenty-one".