218863 has 4 divisors (see below), whose sum is σ = 226440. Its totient is φ = 211288.

The previous prime is 218857. The next prime is 218873. The reversal of 218863 is 368812.

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

It is a cyclic number.

It is not a de Polignac number, because 218863 - 2¹³ = 210671 is a prime.

It is a Duffinian number.

218863 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3745 + ... + 3802.

It is an arithmetic number, because the mean of its divisors is an integer number (56610).

2²¹⁸⁸⁶³ is an apocalyptic number.

218863 is a deficient number, since it is larger than the sum of its proper divisors (7577).

218863 is an equidigital number, since it uses as much as digits as its factorization.

218863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7576.

The product of its digits is 2304, while the sum is 28.

The square root of 218863 is about 467.8279598314. The cubic root of 218863 is about 60.2639299070.

It can be divided in two parts, 218 and 863, that added together give a triangular number (1081 = T₄₆).

The spelling of 218863 in words is "two hundred eighteen thousand, eight hundred sixty-three".