222122221 has 6 divisors (see below), whose sum is σ = 235957130. Its totient is φ = 209055936.

The previous prime is 222122209. The next prime is 222122231. The reversal of 222122221 is 122221222.

It can be written as a sum of positive squares in 3 ways, for example, as 143161225 + 78960996 = 11965^2 + 8886^2 .

It is not a de Polignac number, because 222122221 - 2⁵ = 222122189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 222122195 and 222122204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222122231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 384006 + ... + 384583.

Almost surely, 2^222122221 is an apocalyptic number.

It is an amenable number.

222122221 is a deficient number, since it is larger than the sum of its proper divisors (13834909).

222122221 is an equidigital number, since it uses as much as digits as its factorization.

222122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768623 (or 768606 counting only the distinct ones).

The product of its digits is 128, while the sum is 16.

The square root of 222122221 is about 14903.7653296071. The cubic root of 222122221 is about 605.6159935051.

Adding to 222122221 its reverse (122221222), we get a palindrome (344343443).

Subtracting from 222122221 its reverse (122221222), we obtain a palindrome (99900999).

It can be divided in two parts, 2221 and 22221, that added together give a palindrome (24442).

The spelling of 222122221 in words is "two hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".