222111222122221 has 2 divisors, whose sum is σ = 222111222122222. Its totient is φ = 222111222122220.

The previous prime is 222111222122171. The next prime is 222111222122243. The reversal of 222111222122221 is 122221222111222.

222111222122221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 124576537440996 + 97534684681225 = 11161386^2 + 9875965^2 .

It is a cyclic number.

It is not a de Polignac number, because 222111222122221 - 2²¹ = 222111220025069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (222111222122821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111055611061110 + 111055611061111.

It is an arithmetic number, because the mean of its divisors is an integer number (111055611061111).

Almost surely, 2^{222111222122221} is an apocalyptic number.

It is an amenable number.

222111222122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

222111222122221 is an equidigital number, since it uses as much as digits as its factorization.

222111222122221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1024, while the sum is 25.

Adding to 222111222122221 its reverse (122221222111222), we get a palindrome (344332444233443).

The spelling of 222111222122221 in words is "two hundred twenty-two trillion, one hundred eleven billion, two hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".