21211223223 has 24 divisors (see below), whose sum is σ = 29106131952. Its totient is φ = 13739701248.

The previous prime is 21211223177. The next prime is 21211223291. The reversal of 21211223223 is 32232211212.

It is not a de Polignac number, because 21211223223 - 2²² = 21207028919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21211223223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211223623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1060665 + ... + 1080477.

It is an arithmetic number, because the mean of its divisors is an integer number (1212755498).

Almost surely, 2^21211223223 is an apocalyptic number.

21211223223 is a deficient number, since it is larger than the sum of its proper divisors (7894908729).

21211223223 is a wasteful number, since it uses less digits than its factorization.

21211223223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20095 (or 20052 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

Adding to 21211223223 its reverse (32232211212), we get a palindrome (53443434435).

The spelling of 21211223223 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-three thousand, two hundred twenty-three".