18445218 has 64 divisors (see below), whose sum is σ = 43545600. Its totient is φ = 5149760.

The previous prime is 18445201. The next prime is 18445253. The reversal of 18445218 is 81254481.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43813 + ... + 44231.

It is an arithmetic number, because the mean of its divisors is an integer number (680400).

Almost surely, 2^18445218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18445218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21772800).

18445218 is an abundant number, since it is smaller than the sum of its proper divisors (25100382).

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

18445218 is a wasteful number, since it uses less digits than its factorization.

18445218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487.

The product of its digits is 10240, while the sum is 33.

The square root of 18445218 is about 4294.7896339635. The cubic root of 18445218 is about 264.2173084498.

Adding to 18445218 its reverse (81254481), we get a palindrome (99699699).

The spelling of 18445218 in words is "eighteen million, four hundred forty-five thousand, two hundred eighteen".