211212211121 has 4 divisors (see below), whose sum is σ = 223636458852. Its totient is φ = 198787963392.

The previous prime is 211212211103. The next prime is 211212211157. The reversal of 211212211121 is 121112212112.

211212211121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 100879288225 + 110332922896 = 317615^2 + 332164^2 .

It is a cyclic number.

It is not a de Polignac number, because 211212211121 - 2³⁰ = 210138469297 is a prime.

It is a super-2 number, since 2×211212211121² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 12424247713 = 211212211121 / (2 + 1 + 1 + 2 + 1 + 2 + 2 + 1 + 1 + 1 + 2 + 1).

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 211212211121.

It is not an unprimeable number, because it can be changed into a prime (211212211181) 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 3 ways as a sum of consecutive naturals, for example, 6212123840 + ... + 6212123873.

It is an arithmetic number, because the mean of its divisors is an integer number (55909114713).

Almost surely, 2^211212211121 is an apocalyptic number.

It is an amenable number.

211212211121 is a deficient number, since it is larger than the sum of its proper divisors (12424247731).

211212211121 is a wasteful number, since it uses less digits than its factorization.

211212211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12424247730.

The product of its digits is 32, while the sum is 17.

Adding to 211212211121 its reverse (121112212112), we get a palindrome (332324423233).

Subtracting from 211212211121 its reverse (121112212112), we obtain a palindrome (90099999009).

The spelling of 211212211121 in words is "two hundred eleven billion, two hundred twelve million, two hundred eleven thousand, one hundred twenty-one".