211121221121 has 4 divisors (see below), whose sum is σ = 220300404672. Its totient is φ = 201942037572.

The previous prime is 211121221097. The next prime is 211121221169. The reversal of 211121221121 is 121122121112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211121221121 - 2²⁶ = 211054112257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211121221121.

It is not an unprimeable number, because it can be changed into a prime (211121221621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4589591741 + ... + 4589591786.

It is an arithmetic number, because the mean of its divisors is an integer number (55075101168).

Almost surely, 2^211121221121 is an apocalyptic number.

It is an amenable number.

211121221121 is a deficient number, since it is larger than the sum of its proper divisors (9179183551).

211121221121 is an equidigital number, since it uses as much as digits as its factorization.

211121221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9179183550.

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

Adding to 211121221121 its reverse (121122121112), we get a palindrome (332243342233).

The spelling of 211121221121 in words is "two hundred eleven billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".