218312638 has 16 divisors (see below), whose sum is σ = 340200000. Its totient is φ = 104944672.

The previous prime is 218312597. The next prime is 218312683. The reversal of 218312638 is 836213812.

It is a happy number.

It is a congruent number.

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, 5988 + ... + 21736.

It is an arithmetic number, because the mean of its divisors is an integer number (21262500).

Almost surely, 2^218312638 is an apocalyptic number.

218312638 is a deficient number, since it is larger than the sum of its proper divisors (121887362).

218312638 is a wasteful number, since it uses less digits than its factorization.

218312638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16019.

The product of its digits is 13824, while the sum is 34.

The square root of 218312638 is about 14775.4065257102. The cubic root of 218312638 is about 602.1337344487.

The spelling of 218312638 in words is "two hundred eighteen million, three hundred twelve thousand, six hundred thirty-eight".