21222012213 has 6 divisors (see below), whose sum is σ = 30654017654. Its totient is φ = 14148008136.

The previous prime is 21222012197. The next prime is 21222012221. The reversal of 21222012213 is 31221022212.

It can be written as a sum of positive squares in only one way, i.e., 12758380209 + 8463632004 = 112953^2 + 91998^2 .

It is not a de Polignac number, because 21222012213 - 2⁴ = 21222012197 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 (21222012223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1179000670 + ... + 1179000687.

Almost surely, 2^21222012213 is an apocalyptic number.

It is an amenable number.

21222012213 is a deficient number, since it is larger than the sum of its proper divisors (9432005441).

21222012213 is a wasteful number, since it uses less digits than its factorization.

21222012213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358001363 (or 2358001360 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21222012213 its reverse (31221022212), we get a palindrome (52443034425).

Subtracting 21222012213 from its reverse (31221022212), we obtain a palindrome (9999009999).

The spelling of 21222012213 in words is "twenty-one billion, two hundred twenty-two million, twelve thousand, two hundred thirteen".