211100111220 has 96 divisors (see below), whose sum is σ = 612316454400. Its totient is φ = 54276296704.

The previous prime is 211100111219. The next prime is 211100111269. The reversal of 211100111220 is 22111001112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 211100111196 and 211100111205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1166692 + ... + 1335428.

It is an arithmetic number, because the mean of its divisors is an integer number (6378296400).

Almost surely, 2^211100111220 is an apocalyptic number.

211100111220 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 211100111220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306158227200).

211100111220 is an abundant number, since it is smaller than the sum of its proper divisors (401216343180).

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

211100111220 is a wasteful number, since it uses less digits than its factorization.

211100111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169497 (or 169495 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 211100111220 its reverse (22111001112), we get a palindrome (233211112332).

The spelling of 211100111220 in words is "two hundred eleven billion, one hundred million, one hundred eleven thousand, two hundred twenty".