21012222223 has 4 divisors (see below), whose sum is σ = 21736781640. Its totient is φ = 20287662808.

The previous prime is 21012222221. The next prime is 21012222239. The reversal of 21012222223 is 32222221012.

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 21012222223 - 2¹ = 21012222221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21012222223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012222221) 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, 362279665 + ... + 362279722.

It is an arithmetic number, because the mean of its divisors is an integer number (5434195410).

Almost surely, 2^21012222223 is an apocalyptic number.

21012222223 is a deficient number, since it is larger than the sum of its proper divisors (724559417).

21012222223 is an equidigital number, since it uses as much as digits as its factorization.

21012222223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724559416.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21012222223 its reverse (32222221012), we get a palindrome (53234443235).

The spelling of 21012222223 in words is "twenty-one billion, twelve million, two hundred twenty-two thousand, two hundred twenty-three".