218916394 has 16 divisors (see below), whose sum is σ = 335042568. Its totient is φ = 107241472.

The previous prime is 218916349. The next prime is 218916407. The reversal of 218916394 is 493619812.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 217946169 + 970225 = 14763^2 + 985^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 218916394.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128154 + ... + 129850.

Almost surely, 2^218916394 is an apocalyptic number.

218916394 is a deficient number, since it is larger than the sum of its proper divisors (116126174).

218916394 is a wasteful number, since it uses less digits than its factorization.

218916394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2969.

The product of its digits is 93312, while the sum is 43.

The square root of 218916394 is about 14795.8235323351. The cubic root of 218916394 is about 602.6883018807.

The spelling of 218916394 in words is "two hundred eighteen million, nine hundred sixteen thousand, three hundred ninety-four".