21200111011 has 4 divisors (see below), whose sum is σ = 22121854992. Its totient is φ = 20278367032.

The previous prime is 21200111003. The next prime is 21200111017. The reversal of 21200111011 is 11011100212.

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 21200111011 - 2³ = 21200111003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21200111017) 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, 460871956 + ... + 460872001.

It is an arithmetic number, because the mean of its divisors is an integer number (5530463748).

Almost surely, 2^21200111011 is an apocalyptic number.

21200111011 is a deficient number, since it is larger than the sum of its proper divisors (921743981).

21200111011 is an equidigital number, since it uses as much as digits as its factorization.

21200111011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921743980.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21200111011 its reverse (11011100212), we get a palindrome (32211211223).

The spelling of 21200111011 in words is "twenty-one billion, two hundred million, one hundred eleven thousand, eleven".