242222221 has 4 divisors (see below), whose sum is σ = 243049212. Its totient is φ = 241395232.

The previous prime is 242222209. The next prime is 242222237. The reversal of 242222221 is 122222242.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122222242 = 2 ⋅61111121.

It can be written as a sum of positive squares in 2 ways, for example, as 225330121 + 16892100 = 15011^2 + 4110^2 .

It is a cyclic number.

It is not a de Polignac number, because 242222221 - 2¹⁷ = 242091149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (242222261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 413056 + ... + 413641.

It is an arithmetic number, because the mean of its divisors is an integer number (60762303).

Almost surely, 2^242222221 is an apocalyptic number.

It is an amenable number.

242222221 is a deficient number, since it is larger than the sum of its proper divisors (826991).

242222221 is an equidigital number, since it uses as much as digits as its factorization.

242222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 826990.

The product of its digits is 512, while the sum is 19.

The square root of 242222221 is about 15563.4900006393. The cubic root of 242222221 is about 623.3586552733.

Adding to 242222221 its reverse (122222242), we get a palindrome (364444463).

The spelling of 242222221 in words is "two hundred forty-two million, two hundred twenty-two thousand, two hundred twenty-one".