211221121212 has 36 divisors (see below), whose sum is σ = 565327120176. Its totient is φ = 66265449600.

The previous prime is 211221121193. The next prime is 211221121247. The reversal of 211221121212 is 212121122112.

211221121212 is a `hidden beast` number, since 211 + 221 + 1 + 21 + 212 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×211221121212² (a number of 23 digits) contains 22 as substring.

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 pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 172565664 + ... + 172566887.

It is an arithmetic number, because the mean of its divisors is an integer number (15703531116).

Almost surely, 2^211221121212 is an apocalyptic number.

It is an amenable number.

211221121212 is an abundant number, since it is smaller than the sum of its proper divisors (354105998964).

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

211221121212 is a wasteful number, since it uses less digits than its factorization.

211221121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345132578 (or 345132573 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 211221121212 its reverse (212121122112), we get a palindrome (423342243324).

The spelling of 211221121212 in words is "two hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twelve".