221220112221 has 12 divisors (see below), whose sum is σ = 320029512348. Its totient is φ = 147254220864.

The previous prime is 221220112207. The next prime is 221220112229. The reversal of 221220112221 is 122211022122.

It is a happy number.

221220112221 is a `hidden beast` number, since 221 + 220 + 1 + 1 + 2 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 151310108196 + 69910004025 = 388986^2 + 264405^2 .

It is not a de Polignac number, because 221220112221 - 2²⁵ = 221186557789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221220112194 and 221220112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220112229) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18814960 + ... + 18826713.

It is an arithmetic number, because the mean of its divisors is an integer number (26669126029).

Almost surely, 2^221220112221 is an apocalyptic number.

It is an amenable number.

221220112221 is a deficient number, since it is larger than the sum of its proper divisors (98809400127).

221220112221 is a wasteful number, since it uses less digits than its factorization.

221220112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37642332 (or 37642329 counting only the distinct ones).

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

Adding to 221220112221 its reverse (122211022122), we get a palindrome (343431134343).

Subtracting from 221220112221 its reverse (122211022122), we obtain a palindrome (99009090099).

The spelling of 221220112221 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred twelve thousand, two hundred twenty-one".