222213221 has 2 divisors, whose sum is σ = 222213222. Its totient is φ = 222213220.

The previous prime is 222213217. The next prime is 222213223. The reversal of 222213221 is 122312222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149793121 + 72420100 = 12239^2 + 8510^2 .

It is a cyclic number.

It is not a de Polignac number, because 222213221 - 2² = 222213217 is a prime.

Together with 222213223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 222213221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (222213223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111106610 + 111106611.

It is an arithmetic number, because the mean of its divisors is an integer number (111106611).

Almost surely, 2^222213221 is an apocalyptic number.

It is an amenable number.

222213221 is a deficient number, since it is larger than the sum of its proper divisors (1).

222213221 is an equidigital number, since it uses as much as digits as its factorization.

222213221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 17.

The square root of 222213221 is about 14906.8179367697. The cubic root of 222213221 is about 605.6986860138.

Adding to 222213221 its reverse (122312222), we get a palindrome (344525443).

Subtracting from 222213221 its reverse (122312222), we obtain a palindrome (99900999).

The spelling of 222213221 in words is "two hundred twenty-two million, two hundred thirteen thousand, two hundred twenty-one".