218281728 has 144 divisors (see below), whose sum is σ = 699211520. Its totient is φ = 59056128.

The previous prime is 218281727. The next prime is 218281741. The reversal of 218281728 is 827182812.

218281728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218281727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101076 + ... + 103212.

Almost surely, 2^218281728 is an apocalyptic number.

218281728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218281728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349605760).

218281728 is an abundant number, since it is smaller than the sum of its proper divisors (480929792).

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

218281728 is a wasteful number, since it uses less digits than its factorization.

218281728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2182 (or 2168 counting only the distinct ones).

The product of its digits is 28672, while the sum is 39.

The square root of 218281728 is about 14774.3604937743. The cubic root of 218281728 is about 602.1053152172.

The spelling of 218281728 in words is "two hundred eighteen million, two hundred eighty-one thousand, seven hundred twenty-eight".