16543209 has 4 divisors (see below), whose sum is σ = 22057616. Its totient is φ = 11028804.

The previous prime is 16543207. The next prime is 16543217. The reversal of 16543209 is 90234561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90234561 = 3 ⋅30078187.

It is not a de Polignac number, because 16543209 - 2¹ = 16543207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16543207) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2757199 + ... + 2757204.

It is an arithmetic number, because the mean of its divisors is an integer number (5514404).

Almost surely, 2^16543209 is an apocalyptic number.

It is an amenable number.

16543209 is a deficient number, since it is larger than the sum of its proper divisors (5514407).

16543209 is an equidigital number, since it uses as much as digits as its factorization.

16543209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5514406.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 16543209 is about 4067.3343850733. The cubic root of 16543209 is about 254.8042018699.

The spelling of 16543209 in words is "sixteen million, five hundred forty-three thousand, two hundred nine".