211221121121 has 4 divisors (see below), whose sum is σ = 211422093744. Its totient is φ = 211020148500.

The previous prime is 211221121117. The next prime is 211221121141. The reversal of 211221121121 is 121121122112.

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 211221121121 - 2² = 211221121117 is a prime.

It is a super-2 number, since 2×211221121121² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211221121121.

It is not an unprimeable number, because it can be changed into a prime (211221121141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100484735 + ... + 100486836.

It is an arithmetic number, because the mean of its divisors is an integer number (52855523436).

Almost surely, 2^211221121121 is an apocalyptic number.

It is an amenable number.

211221121121 is a deficient number, since it is larger than the sum of its proper divisors (200972623).

211221121121 is a wasteful number, since it uses less digits than its factorization.

211221121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200972622.

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

Adding to 211221121121 its reverse (121121122112), we get a palindrome (332342243233).

Subtracting from 211221121121 its reverse (121121122112), we obtain a palindrome (90099999009).

The spelling of 211221121121 in words is "two hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred twenty-one".