218388730 has 32 divisors (see below), whose sum is σ = 450118656. Its totient is φ = 74732544.

The previous prime is 218388719. The next prime is 218388761. The reversal of 218388730 is 37883812.

218388730 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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, 37687 + ... + 43093.

It is an arithmetic number, because the mean of its divisors is an integer number (14066208).

Almost surely, 2^218388730 is an apocalyptic number.

218388730 is an abundant number, since it is smaller than the sum of its proper divisors (231729926).

218388730 is a wasteful number, since it uses less digits than its factorization.

218388730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5998.

The product of its (nonzero) digits is 64512, while the sum is 40.

The square root of 218388730 is about 14777.9812559091. The cubic root of 218388730 is about 602.2036834271.

The spelling of 218388730 in words is "two hundred eighteen million, three hundred eighty-eight thousand, seven hundred thirty".