18413209 has 4 divisors (see below), whose sum is σ = 18595620. Its totient is φ = 18230800.

The previous prime is 18413201. The next prime is 18413221. The reversal of 18413209 is 90231481.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90231481 = 101 ⋅893381.

It can be written as a sum of positive squares in 2 ways, for example, as 17264025 + 1149184 = 4155^2 + 1072^2 .

It is a cyclic number.

It is not a de Polignac number, because 18413209 - 2³ = 18413201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18413201) 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 in 3 ways as a sum of consecutive naturals, for example, 91054 + ... + 91255.

It is an arithmetic number, because the mean of its divisors is an integer number (4648905).

Almost surely, 2^18413209 is an apocalyptic number.

It is an amenable number.

18413209 is a deficient number, since it is larger than the sum of its proper divisors (182411).

18413209 is a wasteful number, since it uses less digits than its factorization.

18413209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182410.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 18413209 is about 4291.0615236792. The cubic root of 18413209 is about 264.0643830194.

Subtracting from 18413209 its product of nonzero digits (1728), we obtain a palindrome (18411481).

It can be divided in two parts, 1841 and 3209, that added together give a triangular number (5050 = T₁₀₀).

The spelling of 18413209 in words is "eighteen million, four hundred thirteen thousand, two hundred nine".