221120221121 has 4 divisors (see below), whose sum is σ = 221121165012. Its totient is φ = 221119277232.

The previous prime is 221120221117. The next prime is 221120221151. The reversal of 221120221121 is 121122021122.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 43825329025 + 177294892096 = 209345^2 + 421064^2 .

It is a cyclic number.

It is not a de Polignac number, because 221120221121 - 2² = 221120221117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221120221121.

It is not an unprimeable number, because it can be changed into a prime (221120221151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 175751 + ... + 687843.

It is an arithmetic number, because the mean of its divisors is an integer number (55280291253).

Almost surely, 2^221120221121 is an apocalyptic number.

It is an amenable number.

221120221121 is a deficient number, since it is larger than the sum of its proper divisors (943891).

221120221121 is an equidigital number, since it uses as much as digits as its factorization.

221120221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 943890.

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

Adding to 221120221121 its reverse (121122021122), we get a palindrome (342242242243).

The spelling of 221120221121 in words is "two hundred twenty-one billion, one hundred twenty million, two hundred twenty-one thousand, one hundred twenty-one".