211121212221 has 12 divisors (see below), whose sum is σ = 307913570848. Its totient is φ = 139380993864.

The previous prime is 211121212147. The next prime is 211121212241. The reversal of 211121212221 is 122212121112.

211121212221 is a `hidden beast` number, since 211 + 1 + 21 + 212 + 221 = 666.

It is not a de Polignac number, because 211121212221 - 2⁹ = 211121211709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211121212194 and 211121212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211121212241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 113872435 + ... + 113874288.

Almost surely, 2^211121212221 is an apocalyptic number.

It is an amenable number.

211121212221 is a deficient number, since it is larger than the sum of its proper divisors (96792358627).

211121212221 is a wasteful number, since it uses less digits than its factorization.

211121212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227746832 (or 227746829 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 211121212221 its reverse (122212121112), we get a palindrome (333333333333).

The spelling of 211121212221 in words is "two hundred eleven billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".