218221135 has 16 divisors (see below), whose sum is σ = 287766432. Its totient is φ = 157542400.

The previous prime is 218221111. The next prime is 218221187. The reversal of 218221135 is 531122812.

It is not a de Polignac number, because 218221135 - 2⁷ = 218221007 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6946 + ... + 22015.

It is an arithmetic number, because the mean of its divisors is an integer number (17985402).

Almost surely, 2^218221135 is an apocalyptic number.

218221135 is a deficient number, since it is larger than the sum of its proper divisors (69545297).

218221135 is a wasteful number, since it uses less digits than its factorization.

218221135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29114.

The product of its digits is 960, while the sum is 25.

The square root of 218221135 is about 14772.3097381554. The cubic root of 218221135 is about 602.0495970955.

Adding to 218221135 its reverse (531122812), we get a palindrome (749343947).

The spelling of 218221135 in words is "two hundred eighteen million, two hundred twenty-one thousand, one hundred thirty-five".