21222231213 has 4 divisors (see below), whose sum is σ = 28296308288. Its totient is φ = 14148154140.

The previous prime is 21222231209. The next prime is 21222231259. The reversal of 21222231213 is 31213222212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21222231213 - 2² = 21222231209 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 21222231213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222230213) 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, 3537038533 + ... + 3537038538.

It is an arithmetic number, because the mean of its divisors is an integer number (7074077072).

Almost surely, 2^21222231213 is an apocalyptic number.

It is an amenable number.

21222231213 is a deficient number, since it is larger than the sum of its proper divisors (7074077075).

21222231213 is an equidigital number, since it uses as much as digits as its factorization.

21222231213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7074077074.

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

Adding to 21222231213 its reverse (31213222212), we get a palindrome (52435453425).

Subtracting 21222231213 from its reverse (31213222212), we obtain a palindrome (9990990999).

The spelling of 21222231213 in words is "twenty-one billion, two hundred twenty-two million, two hundred thirty-one thousand, two hundred thirteen".