18326809 has 4 divisors (see below), whose sum is σ = 18409216. Its totient is φ = 18244404.

The previous prime is 18326807. The next prime is 18326813. The reversal of 18326809 is 90862381.

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: 90862381 = 1277 ⋅71153.

It is a cyclic number.

It is not a de Polignac number, because 18326809 - 2¹ = 18326807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18326801) 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, 40869 + ... + 41314.

It is an arithmetic number, because the mean of its divisors is an integer number (4602304).

Almost surely, 2^18326809 is an apocalyptic number.

It is an amenable number.

18326809 is a deficient number, since it is larger than the sum of its proper divisors (82407).

18326809 is an equidigital number, since it uses as much as digits as its factorization.

18326809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82406.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 18326809 is about 4280.9822471017. The cubic root of 18326809 is about 263.6507136606.

The spelling of 18326809 in words is "eighteen million, three hundred twenty-six thousand, eight hundred nine".