218161728 has 112 divisors (see below), whose sum is σ = 645688320. Its totient is φ = 72230400.

The previous prime is 218161721. The next prime is 218161753. The reversal of 218161728 is 827161812.

218161728 is a `hidden beast` number, since 2 + 18 + 1 + 617 + 28 = 666.

218161728 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 218161692 and 218161701.

It is not an unprimeable number, because it can be changed into a prime (218161721) 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, 329718 + ... + 330378.

Almost surely, 2^218161728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218161728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322844160).

218161728 is an abundant number, since it is smaller than the sum of its proper divisors (427526592).

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

218161728 is a wasteful number, since it uses less digits than its factorization.

218161728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873 (or 857 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 218161728 is about 14770.2988459950. The cubic root of 218161728 is about 601.9949595425.

The spelling of 218161728 in words is "two hundred eighteen million, one hundred sixty-one thousand, seven hundred twenty-eight".