218261238 has 32 divisors (see below), whose sum is σ = 473012736. Its totient is φ = 66741408.

The previous prime is 218261231. The next prime is 218261291. The reversal of 218261238 is 832162812.

218261238 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 218261199 and 218261208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218261231) 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, 4131 + ... + 21297.

It is an arithmetic number, because the mean of its divisors is an integer number (14781648).

Almost surely, 2^218261238 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218261238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (236506368).

218261238 is an abundant number, since it is smaller than the sum of its proper divisors (254751498).

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

218261238 is a wasteful number, since it uses less digits than its factorization.

218261238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17348.

The product of its digits is 9216, while the sum is 33.

The square root of 218261238 is about 14773.6670464716. The cubic root of 218261238 is about 602.0864748497.

The spelling of 218261238 in words is "two hundred eighteen million, two hundred sixty-one thousand, two hundred thirty-eight".