16321691 has 2 divisors, whose sum is σ = 16321692. Its totient is φ = 16321690.

The previous prime is 16321681. The next prime is 16321729. The reversal of 16321691 is 19612361.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16321691 - 2¹⁴ = 16305307 is a prime.

It is not a weakly prime, because it can be changed into another prime (16321631) 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, 8160845 + 8160846.

It is an arithmetic number, because the mean of its divisors is an integer number (8160846).

Almost surely, 2^16321691 is an apocalyptic number.

16321691 is a deficient number, since it is larger than the sum of its proper divisors (1).

16321691 is an equidigital number, since it uses as much as digits as its factorization.

16321691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 29.

The square root of 16321691 is about 4040.0112623605. The cubic root of 16321691 is about 253.6617886823.

The spelling of 16321691 in words is "sixteen million, three hundred twenty-one thousand, six hundred ninety-one".