218393 has 6 divisors (see below), whose sum is σ = 254106. Its totient is φ = 187152.

The previous prime is 218389. The next prime is 218401. The reversal of 218393 is 393812.

218393 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 200704 + 17689 = 448^2 + 133^2 .

It is not a de Polignac number, because 218393 - 2² = 218389 is a prime.

It is a super-3 number, since 3×218393³ = 31249091599033371, which contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218363) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2180 + ... + 2277.

It is an arithmetic number, because the mean of its divisors is an integer number (42351).

2²¹⁸³⁹³ is an apocalyptic number.

It is an amenable number.

218393 is a deficient number, since it is larger than the sum of its proper divisors (35713).

218393 is an equidigital number, since it uses as much as digits as its factorization.

218393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4471 (or 4464 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

The square root of 218393 is about 467.3253684533. The cubic root of 218393 is about 60.2207608222.

The spelling of 218393 in words is "two hundred eighteen thousand, three hundred ninety-three".