21211120211 has 4 divisors (see below), whose sum is σ = 21212036952. Its totient is φ = 21210203472.

The previous prime is 21211120207. The next prime is 21211120253. The reversal of 21211120211 is 11202111212.

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 21211120211 - 2² = 21211120207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21211110211) 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, 422741 + ... + 470246.

It is an arithmetic number, because the mean of its divisors is an integer number (5303009238).

Almost surely, 2^21211120211 is an apocalyptic number.

21211120211 is a deficient number, since it is larger than the sum of its proper divisors (916741).

21211120211 is an equidigital number, since it uses as much as digits as its factorization.

21211120211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916740.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21211120211 its reverse (11202111212), we get a palindrome (32413231423).

The spelling of 21211120211 in words is "twenty-one billion, two hundred eleven million, one hundred twenty thousand, two hundred eleven".