221224212 has 144 divisors (see below), whose sum is σ = 645345792. Its totient is φ = 63243840.

The previous prime is 221224193. The next prime is 221224231. The reversal of 221224212 is 212422122.

221224212 is a `hidden beast` number, since 221 + 22 + 421 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (221224193) and next prime (221224231).

It is a Harshad number since it is a multiple of its sum of digits (18).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 974443 + ... + 974669.

It is an arithmetic number, because the mean of its divisors is an integer number (4481568).

Almost surely, 2^221224212 is an apocalyptic number.

221224212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221224212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322672896).

221224212 is an abundant number, since it is smaller than the sum of its proper divisors (424121580).

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

221224212 is a wasteful number, since it uses less digits than its factorization.

221224212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378 (or 373 counting only the distinct ones).

The product of its digits is 256, while the sum is 18.

The square root of 221224212 is about 14873.6079012457. The cubic root of 221224212 is about 604.7987509947.

Adding to 221224212 its reverse (212422122), we get a palindrome (433646334).

The spelling of 221224212 in words is "two hundred twenty-one million, two hundred twenty-four thousand, two hundred twelve".