18209213 has 8 divisors (see below), whose sum is σ = 20048160. Its totient is φ = 16400880.

The previous prime is 18209209. The next prime is 18209231. The reversal of 18209213 is 31290281.

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

It is a cyclic number.

It is not a de Polignac number, because 18209213 - 2² = 18209209 is a prime.

It is a super-3 number, since 3×18209213³ (a number of 23 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18209203) 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, 6395 + ... + 8792.

It is an arithmetic number, because the mean of its divisors is an integer number (2506020).

Almost surely, 2^18209213 is an apocalyptic number.

It is an amenable number.

18209213 is a deficient number, since it is larger than the sum of its proper divisors (1838947).

18209213 is a wasteful number, since it uses less digits than its factorization.

18209213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15307.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 18209213 is about 4267.2254451810. The cubic root of 18209213 is about 263.0855885326.

Adding to 18209213 its reverse (31290281), we get a palindrome (49499494).

The spelling of 18209213 in words is "eighteen million, two hundred nine thousand, two hundred thirteen".