21222323213 has 36 divisors (see below), whose sum is σ = 26870047380. Its totient is φ = 16704769536.

The previous prime is 21222323207. The next prime is 21222323267. The reversal of 21222323213 is 31232322212.

It can be written as a sum of positive squares in 6 ways, for example, as 1107425284 + 20114897929 = 33278^2 + 141827^2 .

It is not a de Polignac number, because 21222323213 - 2⁴ = 21222323197 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 (21222323293) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1624853 + ... + 1637861.

It is an arithmetic number, because the mean of its divisors is an integer number (746390205).

Almost surely, 2^21222323213 is an apocalyptic number.

It is an amenable number.

21222323213 is a deficient number, since it is larger than the sum of its proper divisors (5647724167).

21222323213 is a wasteful number, since it uses less digits than its factorization.

21222323213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13246 (or 13226 counting only the distinct ones).

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

Adding to 21222323213 its reverse (31232322212), we get a palindrome (52454645425).

The spelling of 21222323213 in words is "twenty-one billion, two hundred twenty-two million, three hundred twenty-three thousand, two hundred thirteen".