18208218 has 32 divisors (see below), whose sum is σ = 42747264. Its totient is φ = 5061312.

The previous prime is 18208189. The next prime is 18208231. The reversal of 18208218 is 81280281.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4305 + ... + 7412.

It is an arithmetic number, because the mean of its divisors is an integer number (1335852).

Almost surely, 2^18208218 is an apocalyptic number.

18208218 is an abundant number, since it is smaller than the sum of its proper divisors (24539046).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18208218 is a wasteful number, since it uses less digits than its factorization.

18208218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11766.

The product of its (nonzero) digits is 2048, while the sum is 30.

The square root of 18208218 is about 4267.1088572944. The cubic root of 18208218 is about 263.0807965457.

Adding to 18208218 its reverse (81280281), we get a palindrome (99488499).

The spelling of 18208218 in words is "eighteen million, two hundred eight thousand, two hundred eighteen".