16672321 has 2 divisors, whose sum is σ = 16672322. Its totient is φ = 16672320.

The previous prime is 16672283. The next prime is 16672343. The reversal of 16672321 is 12327661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16646400 + 25921 = 4080^2 + 161^2 .

It is an emirp because it is prime and its reverse (12327661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16672321 - 2⁷ = 16672193 is a prime.

It is a Chen prime.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 16672321.

It is not a weakly prime, because it can be changed into another prime (16672391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8336160 + 8336161.

It is an arithmetic number, because the mean of its divisors is an integer number (8336161).

Almost surely, 2^16672321 is an apocalyptic number.

It is an amenable number.

16672321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16672321 is an equidigital number, since it uses as much as digits as its factorization.

16672321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 16672321 is about 4083.1753574883. The cubic root of 16672321 is about 255.4653606582.

Adding to 16672321 its reverse (12327661), we get a palindrome (28999982).

The spelling of 16672321 in words is "sixteen million, six hundred seventy-two thousand, three hundred twenty-one".