218291 has 4 divisors (see below), whose sum is σ = 229800. Its totient is φ = 206784.

The previous prime is 218287. The next prime is 218357. The reversal of 218291 is 192812.

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 218291 - 2² = 218287 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 218291.

It is not an unprimeable number, because it can be changed into a prime (218191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5726 + ... + 5763.

It is an arithmetic number, because the mean of its divisors is an integer number (57450).

2²¹⁸²⁹¹ is an apocalyptic number.

218291 is a deficient number, since it is larger than the sum of its proper divisors (11509).

218291 is a wasteful number, since it uses less digits than its factorization.

218291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11508.

The product of its digits is 288, while the sum is 23.

The square root of 218291 is about 467.2162240334. The cubic root of 218291 is about 60.2113840349.

The spelling of 218291 in words is "two hundred eighteen thousand, two hundred ninety-one".