21211122211 has 8 divisors (see below), whose sum is σ = 21641979744. Its totient is φ = 20784595200.

The previous prime is 21211122199. The next prime is 21211122227. The reversal of 21211122211 is 11222111212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21211122211 - 2¹⁵ = 21211089443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211122011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1072735 + ... + 1092328.

It is an arithmetic number, because the mean of its divisors is an integer number (2705247468).

Almost surely, 2^21211122211 is an apocalyptic number.

21211122211 is a deficient number, since it is larger than the sum of its proper divisors (430857533).

21211122211 is a wasteful number, since it uses less digits than its factorization.

21211122211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2165261.

The product of its digits is 32, while the sum is 16.

Adding to 21211122211 its reverse (11222111212), we get a palindrome (32433233423).

The spelling of 21211122211 in words is "twenty-one billion, two hundred eleven million, one hundred twenty-two thousand, two hundred eleven".