221144221 has 2 divisors, whose sum is σ = 221144222. Its totient is φ = 221144220.

The previous prime is 221144207. The next prime is 221144237. The reversal of 221144221 is 122441122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140683321 + 80460900 = 11861^2 + 8970^2 .

It is a cyclic number.

It is not a de Polignac number, because 221144221 - 2¹³ = 221136029 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221144281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110572110 + 110572111.

It is an arithmetic number, because the mean of its divisors is an integer number (110572111).

Almost surely, 2^221144221 is an apocalyptic number.

It is an amenable number.

221144221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221144221 is an equidigital number, since it uses as much as digits as its factorization.

221144221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 256, while the sum is 19.

The square root of 221144221 is about 14870.9186333595. The cubic root of 221144221 is about 604.7258471467.

Adding to 221144221 its reverse (122441122), we get a palindrome (343585343).

It can be divided in two parts, 22114 and 4221, that added together give a triangular number (26335 = T₂₂₉).

The spelling of 221144221 in words is "two hundred twenty-one million, one hundred forty-four thousand, two hundred twenty-one".