211221011100 has 144 divisors (see below), whose sum is σ = 670545832320. Its totient is φ = 50908972800.

The previous prime is 211221011051. The next prime is 211221011167. The reversal of 211221011100 is 1110122112.

It is a super-2 number, since 2×211221011100² (a number of 23 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 385911 + ... + 755889.

It is an arithmetic number, because the mean of its divisors is an integer number (4656568280).

Almost surely, 2^211221011100 is an apocalyptic number.

211221011100 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 211221011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (335272916160).

211221011100 is an abundant number, since it is smaller than the sum of its proper divisors (459324821220).

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

211221011100 is a wasteful number, since it uses less digits than its factorization.

211221011100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370180 (or 370173 counting only the distinct ones).

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

Adding to 211221011100 its reverse (1110122112), we get a palindrome (212331133212).

The spelling of 211221011100 in words is "two hundred eleven billion, two hundred twenty-one million, eleven thousand, one hundred".