218211224 has 64 divisors (see below), whose sum is σ = 521026560. Its totient is φ = 83197440.

The previous prime is 218211221. The next prime is 218211239. The reversal of 218211224 is 422112812.

It is a super-2 number, since 2×218211224² = 95232276559156352, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 218211224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218211221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25184 + ... + 32720.

It is an arithmetic number, because the mean of its divisors is an integer number (8141040).

Almost surely, 2^218211224 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 218211224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260513280).

218211224 is an abundant number, since it is smaller than the sum of its proper divisors (302815336).

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

218211224 is a wasteful number, since it uses less digits than its factorization.

218211224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7608 (or 7604 counting only the distinct ones).

The product of its digits is 512, while the sum is 23.

The square root of 218211224 is about 14771.9742756342. The cubic root of 218211224 is about 602.0404824820.

The spelling of 218211224 in words is "two hundred eighteen million, two hundred eleven thousand, two hundred twenty-four".