16564189 has 2 divisors, whose sum is σ = 16564190. Its totient is φ = 16564188.

The previous prime is 16564187. The next prime is 16564193. The reversal of 16564189 is 98146561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13616100 + 2948089 = 3690^2 + 1717^2 .

It is an emirp because it is prime and its reverse (98146561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16564189 - 2¹ = 16564187 is a prime.

Together with 16564187, 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 (16564183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8282094 + 8282095.

It is an arithmetic number, because the mean of its divisors is an integer number (8282095).

Almost surely, 2^16564189 is an apocalyptic number.

It is an amenable number.

16564189 is a deficient number, since it is larger than the sum of its proper divisors (1).

16564189 is an equidigital number, since it uses as much as digits as its factorization.

16564189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 40.

The square root of 16564189 is about 4069.9126526254. The cubic root of 16564189 is about 254.9118700962.

The spelling of 16564189 in words is "sixteen million, five hundred sixty-four thousand, one hundred eighty-nine".