218909317 has 12 divisors (see below), whose sum is σ = 252045216. Its totient is φ = 188530920.

The previous prime is 218909311. The next prime is 218909329. The reversal of 218909317 is 713909812.

It is not a de Polignac number, because 218909317 - 2⁷ = 218909189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 218909317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218909311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23593 + ... + 31534.

It is an arithmetic number, because the mean of its divisors is an integer number (21003768).

Almost surely, 2^218909317 is an apocalyptic number.

It is an amenable number.

218909317 is a deficient number, since it is larger than the sum of its proper divisors (33135899).

218909317 is a wasteful number, since it uses less digits than its factorization.

218909317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55176 (or 55157 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 218909317 is about 14795.5843750762. The cubic root of 218909317 is about 602.6818073601.

The spelling of 218909317 in words is "two hundred eighteen million, nine hundred nine thousand, three hundred seventeen".