13440209 has 4 divisors (see below), whose sum is σ = 13752816. Its totient is φ = 13127604.

The previous prime is 13440199. The next prime is 13440221. The reversal of 13440209 is 90204431.

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: 90204431 = 17 ⋅5306143.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13440209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13440269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156239 + ... + 156324.

It is an arithmetic number, because the mean of its divisors is an integer number (3438204).

Almost surely, 2^13440209 is an apocalyptic number.

It is an amenable number.

13440209 is a deficient number, since it is larger than the sum of its proper divisors (312607).

13440209 is an equidigital number, since it uses as much as digits as its factorization.

13440209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312606.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 13440209 is about 3666.0890605658. The cubic root of 13440209 is about 237.7581105245.

The spelling of 13440209 in words is "thirteen million, four hundred forty thousand, two hundred nine".