21011111223 has 12 divisors (see below), whose sum is σ = 29759683560. Its totient is φ = 13183441792.

The previous prime is 21011111203. The next prime is 21011111237. The reversal of 21011111223 is 32211111012.

It is not a de Polignac number, because 21011111223 - 2²¹ = 21009014071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011111203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12116268 + ... + 12118001.

It is an arithmetic number, because the mean of its divisors is an integer number (2479973630).

Almost surely, 2^21011111223 is an apocalyptic number.

21011111223 is a deficient number, since it is larger than the sum of its proper divisors (8748572337).

21011111223 is a wasteful number, since it uses less digits than its factorization.

21011111223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24234306 (or 24234289 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21011111223 its reverse (32211111012), we get a palindrome (53222222235).

The spelling of 21011111223 in words is "twenty-one billion, eleven million, one hundred eleven thousand, two hundred twenty-three".