16591909 has 2 divisors, whose sum is σ = 16591910. Its totient is φ = 16591908.

The previous prime is 16591907. The next prime is 16591957. The reversal of 16591909 is 90919561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13667809 + 2924100 = 3697^2 + 1710^2 .

It is an emirp because it is prime and its reverse (90919561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16591909 - 2¹ = 16591907 is a prime.

Together with 16591907, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16591907) 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, 8295954 + 8295955.

It is an arithmetic number, because the mean of its divisors is an integer number (8295955).

Almost surely, 2^16591909 is an apocalyptic number.

It is an amenable number.

16591909 is a deficient number, since it is larger than the sum of its proper divisors (1).

16591909 is an equidigital number, since it uses as much as digits as its factorization.

16591909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21870, while the sum is 40.

The square root of 16591909 is about 4073.3167075493. The cubic root of 16591909 is about 255.0539883125.

The spelling of 16591909 in words is "sixteen million, five hundred ninety-one thousand, nine hundred nine".