18100209 has 4 divisors (see below), whose sum is σ = 24133616. Its totient is φ = 12066804.

The previous prime is 18100207. The next prime is 18100211. The reversal of 18100209 is 90200181.

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 an interprime number because it is at equal distance from previous prime (18100207) and next prime (18100211).

It is not a de Polignac number, because 18100209 - 2¹ = 18100207 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18100207) 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, 3016699 + ... + 3016704.

It is an arithmetic number, because the mean of its divisors is an integer number (6033404).

Almost surely, 2^18100209 is an apocalyptic number.

It is an amenable number.

18100209 is a deficient number, since it is larger than the sum of its proper divisors (6033407).

18100209 is an equidigital number, since it uses as much as digits as its factorization.

18100209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6033406.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 18100209 is about 4254.4340399165. The cubic root of 18100209 is about 262.5595765003.

The spelling of 18100209 in words is "eighteen million, one hundred thousand, two hundred nine".