211221222111200 has 144 divisors (see below), whose sum is σ = 589673947451904. Its totient is φ = 72373637107200.

The previous prime is 211221222111187. The next prime is 211221222111227. The reversal of 211221222111200 is 2111222122112.

It is a super-2 number, since 2×211221222111200² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2736356 + ... + 20734755.

It is an arithmetic number, because the mean of its divisors is an integer number (4094957968416).

Almost surely, 2^{211221222111200} is an apocalyptic number.

211221222111200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211221222111200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294836973725952).

211221222111200 is an abundant number, since it is smaller than the sum of its proper divisors (378452725340704).

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

211221222111200 is a wasteful number, since it uses less digits than its factorization.

211221222111200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23472745 (or 23472732 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 211221222111200 its reverse (2111222122112), we get a palindrome (213332444233312).

The spelling of 211221222111200 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twenty-two million, one hundred eleven thousand, two hundred".