211221211222116 has 144 divisors (see below), whose sum is σ = 562788963696960. Its totient is φ = 66717565608960.

The previous prime is 211221211222061. The next prime is 211221211222117. The reversal of 211221211222116 is 611222112122112.

211221211222116 is a `hidden beast` number, since 2 + 1 + 1 + 221 + 211 + 2 + 221 + 1 + 6 = 666.

It is a super-2 number, since 2×211221211222116² (a number of 29 digits) contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 211221211222116.

It is not an unprimeable number, because it can be changed into a prime (211221211222117) 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 47 ways as a sum of consecutive naturals, for example, 2064696 + ... + 20656848.

It is an arithmetic number, because the mean of its divisors is an integer number (3908256692340).

Almost surely, 2^{211221211222116} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211221211222116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281394481848480).

211221211222116 is an abundant number, since it is smaller than the sum of its proper divisors (351567752474844).

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

211221211222116 is a wasteful number, since it uses less digits than its factorization.

211221211222116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18592426 (or 18592421 counting only the distinct ones).

The product of its digits is 768, while the sum is 27.

Adding to 211221211222116 its reverse (611222112122112), we get a palindrome (822443323344228).

The spelling of 211221211222116 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred eleven million, two hundred twenty-two thousand, one hundred sixteen".