221110110111221 has 4 divisors (see below), whose sum is σ = 221110598471244. Its totient is φ = 221109621751200.

The previous prime is 221110110111203. The next prime is 221110110111223. The reversal of 221110110111221 is 122111011011122.

221110110111221 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 114519662320996 + 106590447790225 = 10701386^2 + 10324265^2 .

It is a cyclic number.

It is not a de Polignac number, because 221110110111221 - 2²⁶ = 221110043002357 is a prime.

It is a super-2 number, since 2×221110110111221² (a number of 29 digits) contains 22 as substring.

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 221110110111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221110110111223) 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, 243500240 + ... + 244406601.

It is an arithmetic number, because the mean of its divisors is an integer number (55277649617811).

Almost surely, 2^{221110110111221} is an apocalyptic number.

It is an amenable number.

221110110111221 is a deficient number, since it is larger than the sum of its proper divisors (488360023).

221110110111221 is an equidigital number, since it uses as much as digits as its factorization.

221110110111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488360022.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 221110110111221 its reverse (122111011011122), we get a palindrome (343221121122343).

The spelling of 221110110111221 in words is "two hundred twenty-one trillion, one hundred ten billion, one hundred ten million, one hundred eleven thousand, two hundred twenty-one".