218806 has 8 divisors (see below), whose sum is σ = 375120. Its totient is φ = 93768.

The previous prime is 218797. The next prime is 218809. The reversal of 218806 is 608812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218809) by changing a digit.

218806 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7801 + ... + 7828.

It is an arithmetic number, because the mean of its divisors is an integer number (46890).

2²¹⁸⁸⁰⁶ is an apocalyptic number.

218806 is a deficient number, since it is larger than the sum of its proper divisors (156314).

218806 is a wasteful number, since it uses less digits than its factorization.

218806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15638.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 218806 is about 467.7670360340. The cubic root of 218806 is about 60.2586978025.

It can be divided in two parts, 218 and 806, that added together give a 10-th power (1024 = 2¹⁰).

The spelling of 218806 in words is "two hundred eighteen thousand, eight hundred six".