211221222 has 16 divisors (see below), whose sum is σ = 427533120.
Its totient is φ = 69558632.
The previous prime is 211221169. The next prime is 211221229. The reversal of 211221222 is 222122112.
It is a super-2 number, since 2×2112212222 = 89228809246346568, which contains 22 as substring.
It is a nude number because it is divisible by every one of its digits.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (211221229) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 211572 + ... + 212567.
It is an arithmetic number, because the mean of its divisors is an integer number (26720820).
Almost surely, 2211221222 is an apocalyptic number.
211221222 is an abundant number, since it is smaller than the sum of its proper divisors (216311898).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
211221222 is a wasteful number, since it uses less digits than its factorization.
211221222 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 424227.
The product of its digits is 64, while the sum is 15.
The square root of 211221222 is about 14533.4518267341.
The cubic root of 211221222 is about 595.5421671242.
Adding to 211221222 its reverse (222122112), we get a palindrome (433343334).
The spelling of 211221222 in words is "two hundred eleven million, two hundred twenty-one thousand, two hundred twenty-two".