21010220211 has 4 divisors (see below), whose sum is σ = 28013626952. Its totient is φ = 14006813472.

The previous prime is 21010220191. The next prime is 21010220213. The reversal of 21010220211 is 11202201012.

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

It is not a de Polignac number, because 21010220211 - 2¹⁹ = 21009695923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010220213) 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, 3501703366 + ... + 3501703371.

It is an arithmetic number, because the mean of its divisors is an integer number (7003406738).

Almost surely, 2^21010220211 is an apocalyptic number.

21010220211 is a deficient number, since it is larger than the sum of its proper divisors (7003406741).

21010220211 is an equidigital number, since it uses as much as digits as its factorization.

21010220211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7003406740.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21010220211 its reverse (11202201012), we get a palindrome (32212421223).

The spelling of 21010220211 in words is "twenty-one billion, ten million, two hundred twenty thousand, two hundred eleven".