18009109 has 4 divisors (see below), whose sum is σ = 18590080. Its totient is φ = 17428140.

The previous prime is 18009107. The next prime is 18009119. The reversal of 18009109 is 90190081.

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: 90190081 = 659 ⋅136859.

It is a cyclic number.

It is not a de Polignac number, because 18009109 - 2¹ = 18009107 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18009107) 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, 290439 + ... + 290500.

It is an arithmetic number, because the mean of its divisors is an integer number (4647520).

Almost surely, 2^18009109 is an apocalyptic number.

It is an amenable number.

18009109 is a deficient number, since it is larger than the sum of its proper divisors (580971).

18009109 is an equidigital number, since it uses as much as digits as its factorization.

18009109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580970.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 18009109 is about 4243.7140572852. The cubic root of 18009109 is about 262.1183399905.

The spelling of 18009109 in words is "eighteen million, nine thousand, one hundred nine".