218381814 has 48 divisors (see below), whose sum is σ = 542793888. Its totient is φ = 62159616.

The previous prime is 218381791. The next prime is 218381831. The reversal of 218381814 is 418183812.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 31774 + ... + 38030.

It is an arithmetic number, because the mean of its divisors is an integer number (11308206).

Almost surely, 2^218381814 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218381814, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271396944).

218381814 is an abundant number, since it is smaller than the sum of its proper divisors (324412074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218381814 is a wasteful number, since it uses less digits than its factorization.

218381814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6549 (or 6546 counting only the distinct ones).

The product of its digits is 12288, while the sum is 36.

The square root of 218381814 is about 14777.7472572784. The cubic root of 218381814 is about 602.1973264375.

The spelling of 218381814 in words is "two hundred eighteen million, three hundred eighty-one thousand, eight hundred fourteen".