16008221 has 2 divisors, whose sum is σ = 16008222. Its totient is φ = 16008220.

The previous prime is 16008217. The next prime is 16008229. The reversal of 16008221 is 12280061.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15912121 + 96100 = 3989^2 + 310^2 .

It is a cyclic number.

It is not a de Polignac number, because 16008221 - 2² = 16008217 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16008193 and 16008202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16008229) 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, 8004110 + 8004111.

It is an arithmetic number, because the mean of its divisors is an integer number (8004111).

Almost surely, 2^16008221 is an apocalyptic number.

It is an amenable number.

16008221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16008221 is an equidigital number, since it uses as much as digits as its factorization.

16008221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 16008221 is about 4001.0274930323. The cubic root of 16008221 is about 252.0273601351.

Adding to 16008221 its reverse (12280061), we get a palindrome (28288282).

The spelling of 16008221 in words is "sixteen million, eight thousand, two hundred twenty-one".