21201120211 has 4 divisors (see below), whose sum is σ = 21203271424. Its totient is φ = 21198969000.

The previous prime is 21201120203. The next prime is 21201120221. The reversal of 21201120211 is 11202110212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21201120211 - 2³ = 21201120203 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21201120191 and 21201120200.

It is not an unprimeable number, because it can be changed into a prime (21201120221) 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, 1060755 + ... + 1080556.

It is an arithmetic number, because the mean of its divisors is an integer number (5300817856).

Almost surely, 2^21201120211 is an apocalyptic number.

21201120211 is a deficient number, since it is larger than the sum of its proper divisors (2151213).

21201120211 is an equidigital number, since it uses as much as digits as its factorization.

21201120211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2151212.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21201120211 its reverse (11202110212), we get a palindrome (32403230423).

Subtracting from 21201120211 its reverse (11202110212), we obtain a palindrome (9999009999).

The spelling of 21201120211 in words is "twenty-one billion, two hundred one million, one hundred twenty thousand, two hundred eleven".