211221212 has 6 divisors (see below), whose sum is σ = 369637128. Its totient is φ = 105610604.

The previous prime is 211221169. The next prime is 211221229. The reversal of 211221212 is 212122112.

It is a super-2 number, since 2×211221212² = 89228800797497888, 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 an unprimeable number.

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 as a sum of consecutive naturals, namely, 26402648 + ... + 26402655.

It is an arithmetic number, because the mean of its divisors is an integer number (61606188).

Almost surely, 2^211221212 is an apocalyptic number.

It is an amenable number.

211221212 is a deficient number, since it is larger than the sum of its proper divisors (158415916).

211221212 is a wasteful number, since it uses less digits than its factorization.

211221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52805307 (or 52805305 counting only the distinct ones).

The product of its digits is 32, while the sum is 14.

The square root of 211221212 is about 14533.4514827002. The cubic root of 211221212 is about 595.5421577258.

Adding to 211221212 its reverse (212122112), we get a palindrome (423343324).

It can be divided in two parts, 2112 and 21212, that multiplied together give a palindrome (44799744).

The spelling of 211221212 in words is "two hundred eleven million, two hundred twenty-one thousand, two hundred twelve".