21021223223 has 32 divisors (see below), whose sum is σ = 28503885312. Its totient is φ = 14970384000.

The previous prime is 21021223213. The next prime is 21021223241. The reversal of 21021223223 is 32232212012.

It is a happy number.

It is not a de Polignac number, because 21021223223 - 2¹⁸ = 21020961079 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21021223195 and 21021223204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021223213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2861 + ... + 205062.

It is an arithmetic number, because the mean of its divisors is an integer number (890746416).

Almost surely, 2^21021223223 is an apocalyptic number.

21021223223 is a deficient number, since it is larger than the sum of its proper divisors (7482662089).

21021223223 is a wasteful number, since it uses less digits than its factorization.

21021223223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208055.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21021223223 its reverse (32232212012), we get a palindrome (53253435235).

The spelling of 21021223223 in words is "twenty-one billion, twenty-one million, two hundred twenty-three thousand, two hundred twenty-three".