18101209 has 8 divisors (see below), whose sum is σ = 21904128. Its totient is φ = 14602560.

The previous prime is 18101203. The next prime is 18101227. The reversal of 18101209 is 90210181.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18101209 - 2⁷ = 18101081 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18101209.

It is not an unprimeable number, because it can be changed into a prime (18101203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75937 + ... + 76174.

It is an arithmetic number, because the mean of its divisors is an integer number (2738016).

Almost surely, 2^18101209 is an apocalyptic number.

It is an amenable number.

18101209 is a deficient number, since it is larger than the sum of its proper divisors (3802919).

18101209 is a wasteful number, since it uses less digits than its factorization.

18101209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152135.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 18101209 is about 4254.5515627384. The cubic root of 18101209 is about 262.5644117067.

The spelling of 18101209 in words is "eighteen million, one hundred one thousand, two hundred nine".