218212218 has 80 divisors (see below), whose sum is σ = 561447744. Its totient is φ = 62052480.

The previous prime is 218212213. The next prime is 218212231. The reversal of 218212218 is 812212812.

218212218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×218212218³ (a number of 26 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 218212191 and 218212200.

It is not an unprimeable number, because it can be changed into a prime (218212213) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 381873 + ... + 382443.

Almost surely, 2^218212218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218212218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280723872).

218212218 is an abundant number, since it is smaller than the sum of its proper divisors (343235526).

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

218212218 is a wasteful number, since it uses less digits than its factorization.

218212218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 929 (or 920 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 218212218 is about 14772.0079203878. The cubic root of 218212218 is about 602.0413966228.

It can be divided in two parts, 2182 and 12218, that added together give a square (14400 = 120²).

The spelling of 218212218 in words is "two hundred eighteen million, two hundred twelve thousand, two hundred eighteen".