16005221 has 2 divisors, whose sum is σ = 16005222. Its totient is φ = 16005220.

The previous prime is 16005193. The next prime is 16005229. The reversal of 16005221 is 12250061.

16005221 is nontrivially palindromic in base 12.

16005221 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., 11296321 + 4708900 = 3361^2 + 2170^2 .

It is an emirp because it is prime and its reverse (12250061) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16005221 - 2¹⁴ = 15988837 is a prime.

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 16005221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16005229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8002610 + 8002611.

It is an arithmetic number, because the mean of its divisors is an integer number (8002611).

Almost surely, 2^16005221 is an apocalyptic number.

It is an amenable number.

16005221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16005221 is an equidigital number, since it uses as much as digits as its factorization.

16005221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 16005221 is about 4000.6525717688. The cubic root of 16005221 is about 252.0116155308.

Adding to 16005221 its reverse (12250061), we get a palindrome (28255282).

The spelling of 16005221 in words is "sixteen million, five thousand, two hundred twenty-one".