16091321 has 2 divisors, whose sum is σ = 16091322. Its totient is φ = 16091320.

The previous prime is 16091303. The next prime is 16091353. The reversal of 16091321 is 12319061.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9517225 + 6574096 = 3085^2 + 2564^2 .

It is an emirp because it is prime and its reverse (12319061) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16091321 is a prime.

It is a super-2 number, since 2×16091321² = 517861223050082, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16091371) 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, 8045660 + 8045661.

It is an arithmetic number, because the mean of its divisors is an integer number (8045661).

Almost surely, 2^16091321 is an apocalyptic number.

It is an amenable number.

16091321 is a deficient number, since it is larger than the sum of its proper divisors (1).

16091321 is an equidigital number, since it uses as much as digits as its factorization.

16091321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 16091321 is about 4011.3988831828. The cubic root of 16091321 is about 252.4627059909.

The spelling of 16091321 in words is "sixteen million, ninety-one thousand, three hundred twenty-one".