18640218 has 8 divisors (see below), whose sum is σ = 37280448. Its totient is φ = 6213404.

The previous prime is 18640103. The next prime is 18640241. The reversal of 18640218 is 81204681.

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

18640218 is an admirable number.

It is a super-3 number, since 3×18640218³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1553346 + ... + 1553357.

It is an arithmetic number, because the mean of its divisors is an integer number (4660056).

Almost surely, 2^18640218 is an apocalyptic number.

18640218 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18640218 is a wasteful number, since it uses less digits than its factorization.

18640218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3106708.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 18640218 is about 4317.4318755482. The cubic root of 18640218 is about 265.1451346909.

Adding to 18640218 its reverse (81204681), we get a palindrome (99844899).

It can be divided in two parts, 186 and 40218, that added together give a palindrome (40404).

The spelling of 18640218 in words is "eighteen million, six hundred forty thousand, two hundred eighteen".