13564209 has 4 divisors (see below), whose sum is σ = 18085616. Its totient is φ = 9042804.

The previous prime is 13564207. The next prime is 13564211. The reversal of 13564209 is 90246531.

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: 90246531 = 3 ⋅30082177.

It is an interprime number because it is at equal distance from previous prime (13564207) and next prime (13564211).

It is not a de Polignac number, because 13564209 - 2¹ = 13564207 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13564207) 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, 2260699 + ... + 2260704.

It is an arithmetic number, because the mean of its divisors is an integer number (4521404).

Almost surely, 2^13564209 is an apocalyptic number.

It is an amenable number.

13564209 is a deficient number, since it is larger than the sum of its proper divisors (4521407).

13564209 is an equidigital number, since it uses as much as digits as its factorization.

13564209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4521406.

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

The square root of 13564209 is about 3682.9619873140. The cubic root of 13564209 is about 238.4870624858.

It can be divided in two parts, 1356 and 4209, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 13564209 in words is "thirteen million, five hundred sixty-four thousand, two hundred nine".