218180 has 12 divisors (see below), whose sum is σ = 458220. Its totient is φ = 87264.

The previous prime is 218171. The next prime is 218191. The reversal of 218180 is 81812.

It can be written as a sum of positive squares in 2 ways, for example, as 64516 + 153664 = 254^2 + 392^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 10909 = 218180 / (2 + 1 + 8 + 1 + 8 + 0).

It is an unprimeable number.

218180 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 (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5435 + ... + 5474.

It is an arithmetic number, because the mean of its divisors is an integer number (38185).

2²¹⁸¹⁸⁰ is an apocalyptic number.

218180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218180 is an abundant number, since it is smaller than the sum of its proper divisors (240040).

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

218180 is a wasteful number, since it uses less digits than its factorization.

218180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10918 (or 10916 counting only the distinct ones).

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

The square root of 218180 is about 467.0974202455. The cubic root of 218180 is about 60.2011765645.

Adding to 218180 its reverse (81812), we get a palindrome (299992).

The spelling of 218180 in words is "two hundred eighteen thousand, one hundred eighty".