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18218 = 29109
BaseRepresentation
bin100011100101010
3220222202
410130222
51040333
6220202
7104054
oct43452
926882
1018218
1112762
12a662
1383a5
1468d4
1555e8
hex472a

18218 has 4 divisors (see below), whose sum is σ = 27330. Its totient is φ = 9108.

The previous prime is 18217. The next prime is 18223. The reversal of 18218 is 81281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17689 + 529 = 133^2 + 23^2 .

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 18218.

It is not an unprimeable number, because it can be changed into a prime (18211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4553 + ... + 4556.

218218 is an apocalyptic number.

18218 is a deficient number, since it is larger than the sum of its proper divisors (9112).

18218 is an equidigital number, since it uses as much as digits as its factorization.

18218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9111.

The product of its digits is 128, while the sum is 20.

The square root of 18218 is about 134.9740715841. The cubic root of 18218 is about 26.3127899739.

Adding to 18218 its reverse (81281), we get a palindrome (99499).

The spelling of 18218 in words is "eighteen thousand, two hundred eighteen".

Divisors: 1 2 9109 18218