18218205 has 12 divisors (see below), whose sum is σ = 31578300. Its totient is φ = 9716352.

The previous prime is 18218191. The next prime is 18218209. The reversal of 18218205 is 50281281.

It can be written as a sum of positive squares in 2 ways, for example, as 10830681 + 7387524 = 3291^2 + 2718^2 .

It is not a de Polignac number, because 18218205 - 2¹¹ = 18216157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18218209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 202380 + ... + 202469.

It is an arithmetic number, because the mean of its divisors is an integer number (2631525).

Almost surely, 2^18218205 is an apocalyptic number.

18218205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18218205 is a deficient number, since it is larger than the sum of its proper divisors (13360095).

18218205 is a wasteful number, since it uses less digits than its factorization.

18218205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404860 (or 404857 counting only the distinct ones).

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

The square root of 18218205 is about 4268.2789271555. The cubic root of 18218205 is about 263.1288866938.

Adding to 18218205 its reverse (50281281), we get a palindrome (68499486).

The spelling of 18218205 in words is "eighteen million, two hundred eighteen thousand, two hundred five".