18198009 has 12 divisors (see below), whose sum is σ = 26343252. Its totient is φ = 12105600.

The previous prime is 18198001. The next prime is 18198017. The reversal of 18198009 is 90089181.

It is an interprime number because it is at equal distance from previous prime (18198001) and next prime (18198017).

It can be written as a sum of positive squares in 2 ways, for example, as 8294400 + 9903609 = 2880^2 + 3147^2 .

It is not a de Polignac number, because 18198009 - 2³ = 18198001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18198001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2749 + ... + 6629.

It is an arithmetic number, because the mean of its divisors is an integer number (2195271).

Almost surely, 2^18198009 is an apocalyptic number.

It is an amenable number.

18198009 is a deficient number, since it is larger than the sum of its proper divisors (8145243).

18198009 is a wasteful number, since it uses less digits than its factorization.

18198009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4408 (or 4405 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 18198009 is about 4265.9124463589. The cubic root of 18198009 is about 263.0316192280.

The spelling of 18198009 in words is "eighteen million, one hundred ninety-eight thousand, nine".