212121011100 has 144 divisors (see below), whose sum is σ = 630640886400. Its totient is φ = 55009163520.

The previous prime is 212121011099. The next prime is 212121011101. The reversal of 212121011100 is 1110121212.

212121011100 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (212121011099) and next prime (212121011101).

It is a super-3 number, since 3×212121011100³ (a number of 35 digits) contains 333 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 not an unprimeable number, because it can be changed into a prime (212121011101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31287511 + ... + 31294289.

It is an arithmetic number, because the mean of its divisors is an integer number (4379450600).

Almost surely, 2^212121011100 is an apocalyptic number.

212121011100 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 212121011100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315320443200).

212121011100 is an abundant number, since it is smaller than the sum of its proper divisors (418519875300).

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

212121011100 is a wasteful number, since it uses less digits than its factorization.

212121011100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9652 (or 9645 counting only the distinct ones).

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

Adding to 212121011100 its reverse (1110121212), we get a palindrome (213231132312).

The spelling of 212121011100 in words is "two hundred twelve billion, one hundred twenty-one million, eleven thousand, one hundred".