218812728 has 32 divisors (see below), whose sum is σ = 548246160. Its totient is φ = 72775680.

The previous prime is 218812723. The next prime is 218812747. The reversal of 218812728 is 827218812.

218812728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×218812728³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218812723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1176 + ... + 20952.

Almost surely, 2^218812728 is an apocalyptic number.

It is an amenable number.

218812728 is an abundant number, since it is smaller than the sum of its proper divisors (329433432).

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

218812728 is a wasteful number, since it uses less digits than its factorization.

218812728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20247 (or 20243 counting only the distinct ones).

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

The square root of 218812728 is about 14792.3198991909. The cubic root of 218812728 is about 602.5931542173.

The spelling of 218812728 in words is "two hundred eighteen million, eight hundred twelve thousand, seven hundred twenty-eight".