21021112011 has 4 divisors (see below), whose sum is σ = 28028149352. Its totient is φ = 14014074672.

The previous prime is 21021112003. The next prime is 21021112027. The reversal of 21021112011 is 11021112012.

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

It is not a de Polignac number, because 21021112011 - 2³ = 21021112003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021112111) 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, 3503518666 + ... + 3503518671.

It is an arithmetic number, because the mean of its divisors is an integer number (7007037338).

Almost surely, 2^21021112011 is an apocalyptic number.

21021112011 is a deficient number, since it is larger than the sum of its proper divisors (7007037341).

21021112011 is an equidigital number, since it uses as much as digits as its factorization.

21021112011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7007037340.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21021112011 its reverse (11021112012), we get a palindrome (32042224023).

Subtracting from 21021112011 its reverse (11021112012), we obtain a palindrome (9999999999).

It can be divided in two parts, 210211 and 12011, that added together give a palindrome (222222).

The spelling of 21021112011 in words is "twenty-one billion, twenty-one million, one hundred twelve thousand, eleven".