18418009 has 4 divisors (see below), whose sum is σ = 19218816. Its totient is φ = 17617204.

The previous prime is 18418003. The next prime is 18418019. The reversal of 18418009 is 90081481.

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.

It is a cyclic number.

It is not a de Polignac number, because 18418009 - 2⁷ = 18417881 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18418003) 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, 400369 + ... + 400414.

It is an arithmetic number, because the mean of its divisors is an integer number (4804704).

Almost surely, 2^18418009 is an apocalyptic number.

It is an amenable number.

18418009 is a deficient number, since it is larger than the sum of its proper divisors (800807).

18418009 is an equidigital number, since it uses as much as digits as its factorization.

18418009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800806.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 18418009 is about 4291.6207893988. The cubic root of 18418009 is about 264.0873266739.

The spelling of 18418009 in words is "eighteen million, four hundred eighteen thousand, nine".