21223023231 has 16 divisors (see below), whose sum is σ = 28365036768. Its totient is φ = 14114889600.

The previous prime is 21223023229. The next prime is 21223023259. The reversal of 21223023231 is 13232032212.

It is a happy number.

It is not a de Polignac number, because 21223023231 - 2¹ = 21223023229 is a prime.

It is a super-2 number, since 2×21223023231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21223023198 and 21223023207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223023271) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2313105 + ... + 2322261.

It is an arithmetic number, because the mean of its divisors is an integer number (1772814798).

Almost surely, 2^21223023231 is an apocalyptic number.

21223023231 is a deficient number, since it is larger than the sum of its proper divisors (7142013537).

21223023231 is an equidigital number, since it uses as much as digits as its factorization.

21223023231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10922.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21223023231 its reverse (13232032212), we get a palindrome (34455055443).

The spelling of 21223023231 in words is "twenty-one billion, two hundred twenty-three million, twenty-three thousand, two hundred thirty-one".