221311112221 has 4 divisors (see below), whose sum is σ = 221313116700. Its totient is φ = 221309107744.

The previous prime is 221311112213. The next prime is 221311112251. The reversal of 221311112221 is 122211113122.

221311112221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 125124912900 + 96186199321 = 353730^2 + 310139^2 .

It is a cyclic number.

It is not a de Polignac number, because 221311112221 - 2³ = 221311112213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221311112251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 826336 + ... + 1060873.

It is an arithmetic number, because the mean of its divisors is an integer number (55328279175).

Almost surely, 2^221311112221 is an apocalyptic number.

It is an amenable number.

221311112221 is a deficient number, since it is larger than the sum of its proper divisors (2004479).

221311112221 is a wasteful number, since it uses less digits than its factorization.

221311112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2004478.

The product of its digits is 96, while the sum is 19.

Adding to 221311112221 its reverse (122211113122), we get a palindrome (343522225343).

Subtracting from 221311112221 its reverse (122211113122), we obtain a palindrome (99099999099).

The spelling of 221311112221 in words is "two hundred twenty-one billion, three hundred eleven million, one hundred twelve thousand, two hundred twenty-one".