11220561222221 has 4 divisors (see below), whose sum is σ = 12083681316252. Its totient is φ = 10357441128192.

The previous prime is 11220561222217. The next prime is 11220561222223. The reversal of 11220561222221 is 12222216502211.

11220561222221 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 6168338500996 + 5052222721225 = 2483614^2 + 2247715^2 .

It is a cyclic number.

It is not a de Polignac number, because 11220561222221 - 2² = 11220561222217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11220561222223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 431560046996 + ... + 431560047021.

It is an arithmetic number, because the mean of its divisors is an integer number (3020920329063).

Almost surely, 2^{11220561222221} is an apocalyptic number.

It is an amenable number.

11220561222221 is a deficient number, since it is larger than the sum of its proper divisors (863120094031).

11220561222221 is an equidigital number, since it uses as much as digits as its factorization.

11220561222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863120094030.

The product of its (nonzero) digits is 3840, while the sum is 29.

Adding to 11220561222221 its reverse (12222216502211), we get a palindrome (23442777724432).

The spelling of 11220561222221 in words is "eleven trillion, two hundred twenty billion, five hundred sixty-one million, two hundred twenty-two thousand, two hundred twenty-one".