18133218 has 12 divisors (see below), whose sum is σ = 39288678. Its totient is φ = 6044400.

The previous prime is 18133217. The next prime is 18133279. The reversal of 18133218 is 81233181.

It can be written as a sum of positive squares in only one way, i.e., 13860729 + 4272489 = 3723^2 + 2067^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18133191 and 18133200.

It is not an unprimeable number, because it can be changed into a prime (18133217) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 503683 + ... + 503718.

Almost surely, 2^18133218 is an apocalyptic number.

18133218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18133218 is an abundant number, since it is smaller than the sum of its proper divisors (21155460).

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

18133218 is a wasteful number, since it uses less digits than its factorization.

18133218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1007409 (or 1007406 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 18133218 is about 4258.3116372572. The cubic root of 18133218 is about 262.7190878423.

Adding to 18133218 its reverse (81233181), we get a palindrome (99366399).

The spelling of 18133218 in words is "eighteen million, one hundred thirty-three thousand, two hundred eighteen".