133218 has 16 divisors (see below), whose sum is σ = 296160. Its totient is φ = 44388.

The previous prime is 133213. The next prime is 133241. The reversal of 133218 is 812331.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a self number, because there is not a number n which added to its sum of digits gives 133218.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 133218.

It is not an unprimeable number, because it can be changed into a prime (133213) by changing a digit.

133218 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1180 + ... + 1287.

It is an arithmetic number, because the mean of its divisors is an integer number (18510).

2¹³³²¹⁸ is an apocalyptic number.

133218 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

133218 is an abundant number, since it is smaller than the sum of its proper divisors (162942).

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

133218 is a wasteful number, since it uses less digits than its factorization.

133218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2478 (or 2472 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 133218 is about 364.9904108329. The cubic root of 133218 is about 51.0725610735.

Adding to 133218 its reverse (812331), we get a palindrome (945549).

It can be divided in two parts, 133 and 218, that added together give a triangular number (351 = T₂₆).

The spelling of 133218 in words is "one hundred thirty-three thousand, two hundred eighteen".