21021222213 has 12 divisors (see below), whose sum is σ = 30664622508. Its totient is φ = 13875393600.

The previous prime is 21021222179. The next prime is 21021222221. The reversal of 21021222213 is 31222212012.

21021222213 is a `hidden beast` number, since 210 + 21 + 222 + 213 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17440635969 + 3580586244 = 132063^2 + 59838^2 .

It is not a de Polignac number, because 21021222213 - 2³⁰ = 19947480389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021222913) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11561920 + ... + 11563737.

It is an arithmetic number, because the mean of its divisors is an integer number (2555385209).

Almost surely, 2^21021222213 is an apocalyptic number.

It is an amenable number.

21021222213 is a deficient number, since it is larger than the sum of its proper divisors (9643400295).

21021222213 is a wasteful number, since it uses less digits than its factorization.

21021222213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23125764 (or 23125761 counting only the distinct ones).

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

Adding to 21021222213 its reverse (31222212012), we get a palindrome (52243434225).

The spelling of 21021222213 in words is "twenty-one billion, twenty-one million, two hundred twenty-two thousand, two hundred thirteen".