21100222111 has 4 divisors (see below), whose sum is σ = 21317750272. Its totient is φ = 20882693952.

The previous prime is 21100222109. The next prime is 21100222123. The reversal of 21100222111 is 11122200112.

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 21100222111 - 2¹ = 21100222109 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100222091 and 21100222100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100222211) 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, 108763935 + ... + 108764128.

It is an arithmetic number, because the mean of its divisors is an integer number (5329437568).

Almost surely, 2^21100222111 is an apocalyptic number.

21100222111 is a deficient number, since it is larger than the sum of its proper divisors (217528161).

21100222111 is an equidigital number, since it uses as much as digits as its factorization.

21100222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217528160.

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

Adding to 21100222111 its reverse (11122200112), we get a palindrome (32222422223).

The spelling of 21100222111 in words is "twenty-one billion, one hundred million, two hundred twenty-two thousand, one hundred eleven".