21232223213 has 6 divisors (see below), whose sum is σ = 21586002282. Its totient is φ = 20884150320.

The previous prime is 21232223191. The next prime is 21232223261. The reversal of 21232223213 is 31232223212.

It can be written as a sum of positive squares in 3 ways, for example, as 83210884 + 21149012329 = 9122^2 + 145427^2 .

It is not a de Polignac number, because 21232223213 - 2¹⁰ = 21232222189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232223413) 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 5 ways as a sum of consecutive naturals, for example, 2849306 + ... + 2856747.

It is an arithmetic number, because the mean of its divisors is an integer number (3597667047).

Almost surely, 2^21232223213 is an apocalyptic number.

It is an amenable number.

21232223213 is a deficient number, since it is larger than the sum of its proper divisors (353779069).

21232223213 is an frugal number, since it uses more digits than its factorization.

21232223213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5706175 (or 5706114 counting only the distinct ones).

The product of its digits is 1728, while the sum is 23.

Adding to 21232223213 its reverse (31232223212), we get a palindrome (52464446425).

Subtracting 21232223213 from its reverse (31232223212), we obtain a palindrome (9999999999).

The spelling of 21232223213 in words is "twenty-one billion, two hundred thirty-two million, two hundred twenty-three thousand, two hundred thirteen".