221320213 has 2 divisors, whose sum is σ = 221320214. Its totient is φ = 221320212.

The previous prime is 221320201. The next prime is 221320217. The reversal of 221320213 is 312023122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 172081924 + 49238289 = 13118^2 + 7017^2 .

It is a cyclic number.

It is not a de Polignac number, because 221320213 - 2⁹ = 221319701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221320217) 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 as a sum of consecutive naturals, namely, 110660106 + 110660107.

It is an arithmetic number, because the mean of its divisors is an integer number (110660107).

Almost surely, 2^221320213 is an apocalyptic number.

It is an amenable number.

221320213 is a deficient number, since it is larger than the sum of its proper divisors (1).

221320213 is an equidigital number, since it uses as much as digits as its factorization.

221320213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 221320213 is about 14876.8347775997. The cubic root of 221320213 is about 604.8862231687.

Adding to 221320213 its reverse (312023122), we get a palindrome (533343335).

The spelling of 221320213 in words is "two hundred twenty-one million, three hundred twenty thousand, two hundred thirteen".