18390218 has 16 divisors (see below), whose sum is σ = 34392384. Its totient is φ = 7164960.

The previous prime is 18390199. The next prime is 18390257. The reversal of 18390218 is 81209381.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59555 + ... + 59862.

It is an arithmetic number, because the mean of its divisors is an integer number (2149524).

Almost surely, 2^18390218 is an apocalyptic number.

18390218 is a deficient number, since it is larger than the sum of its proper divisors (16002166).

18390218 is a wasteful number, since it uses less digits than its factorization.

18390218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119437.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18390218 is about 4288.3817460669. The cubic root of 18390218 is about 263.9544323710.

Adding to 18390218 its reverse (81209381), we get a palindrome (99599599).

The spelling of 18390218 in words is "eighteen million, three hundred ninety thousand, two hundred eighteen".