18205218 has 24 divisors (see below), whose sum is σ = 39534768. Its totient is φ = 6054552.

The previous prime is 18205183. The next prime is 18205237. The reversal of 18205218 is 81250281.

It is a junction number, because it is equal to n+sod(n) for n = 18205191 and 18205200.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9705 + ... + 11427.

It is an arithmetic number, because the mean of its divisors is an integer number (1647282).

Almost surely, 2^18205218 is an apocalyptic number.

18205218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18205218 is an abundant number, since it is smaller than the sum of its proper divisors (21329550).

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

18205218 is a wasteful number, since it uses less digits than its factorization.

18205218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2318 (or 2315 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 18205218 is about 4266.7573167454. The cubic root of 18205218 is about 263.0663472874.

Adding to 18205218 its reverse (81250281), we get a palindrome (99455499).

The spelling of 18205218 in words is "eighteen million, two hundred five thousand, two hundred eighteen".