21120111211 has 8 divisors (see below), whose sum is σ = 22882528944. Its totient is φ = 19415477760.

The previous prime is 21120111209. The next prime is 21120111227. The reversal of 21120111211 is 11211102112.

It is a happy number.

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 21120111211 - 2¹ = 21120111209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120111191 and 21120111200.

It is not an unprimeable number, because it can be changed into a prime (21120111251) 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, 14445310 + ... + 14446771.

It is an arithmetic number, because the mean of its divisors is an integer number (2860316118).

Almost surely, 2^21120111211 is an apocalyptic number.

21120111211 is a deficient number, since it is larger than the sum of its proper divisors (1762417733).

21120111211 is a wasteful number, since it uses less digits than its factorization.

21120111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28892141.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21120111211 its reverse (11211102112), we get a palindrome (32331213323).

Subtracting from 21120111211 its reverse (11211102112), we obtain a palindrome (9909009099).

The spelling of 21120111211 in words is "twenty-one billion, one hundred twenty million, one hundred eleven thousand, two hundred eleven".