18897209 has 8 divisors (see below), whose sum is σ = 19136160. Its totient is φ = 18660096.

The previous prime is 18897173. The next prime is 18897227. The reversal of 18897209 is 90279881.

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 18897209 - 2¹² = 18893113 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 18897209.

It is not an unprimeable number, because it can be changed into a prime (18897509) 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, 34274 + ... + 34820.

It is an arithmetic number, because the mean of its divisors is an integer number (2392020).

Almost surely, 2^18897209 is an apocalyptic number.

It is an amenable number.

18897209 is a deficient number, since it is larger than the sum of its proper divisors (238951).

18897209 is a wasteful number, since it uses less digits than its factorization.

18897209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 18897209 is about 4347.0920165094. The cubic root of 18897209 is about 266.3580880251.

The spelling of 18897209 in words is "eighteen million, eight hundred ninety-seven thousand, two hundred nine".