218091 has 8 divisors (see below), whose sum is σ = 293440. Its totient is φ = 144072.

The previous prime is 218087. The next prime is 218107. The reversal of 218091 is 190812.

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

It is not a de Polignac number, because 218091 - 2² = 218087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156 + ... + 678.

It is an arithmetic number, because the mean of its divisors is an integer number (36680).

2²¹⁸⁰⁹¹ is an apocalyptic number.

218091 is a deficient number, since it is larger than the sum of its proper divisors (75349).

218091 is a wasteful number, since it uses less digits than its factorization.

218091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665.

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 218091 is about 467.0021413227. The cubic root of 218091 is about 60.1929896952.

The spelling of 218091 in words is "two hundred eighteen thousand, ninety-one".