211221111222 has 24 divisors (see below), whose sum is σ = 499249899720. Its totient is φ = 64006397280.

The previous prime is 211221111217. The next prime is 211221111253. The reversal of 211221111222 is 222111122112.

211221111222 is a `hidden beast` number, since 211 + 221 + 1 + 11 + 222 = 666.

It is a super-2 number, since 2×211221111222² (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 junction number, because it is equal to n+sod(n) for n = 211221111195 and 211221111204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 533386447 + ... + 533386842.

It is an arithmetic number, because the mean of its divisors is an integer number (20802079155).

Almost surely, 2^211221111222 is an apocalyptic number.

211221111222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

211221111222 is an abundant number, since it is smaller than the sum of its proper divisors (288028788498).

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

211221111222 is a wasteful number, since it uses less digits than its factorization.

211221111222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1066773308 (or 1066773305 counting only the distinct ones).

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

Adding to 211221111222 its reverse (222111122112), we get a palindrome (433332233334).

The spelling of 211221111222 in words is "two hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-two".