173216221 has 2 divisors, whose sum is σ = 173216222. Its totient is φ = 173216220.

The previous prime is 173216119. The next prime is 173216227. The reversal of 173216221 is 122612371.

It is a happy number.

173216221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169260100 + 3956121 = 13010^2 + 1989^2 .

It is a cyclic number.

It is not a de Polignac number, because 173216221 - 2⁹ = 173215709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (173216227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86608110 + 86608111.

It is an arithmetic number, because the mean of its divisors is an integer number (86608111).

Almost surely, 2^173216221 is an apocalyptic number.

It is an amenable number.

173216221 is a deficient number, since it is larger than the sum of its proper divisors (1).

173216221 is an equidigital number, since it uses as much as digits as its factorization.

173216221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 173216221 is about 13161.1633604328. The cubic root of 173216221 is about 557.4375067194.

Adding to 173216221 its reverse (122612371), we get a palindrome (295828592).

The spelling of 173216221 in words is "one hundred seventy-three million, two hundred sixteen thousand, two hundred twenty-one".