21234252213 has 12 divisors (see below), whose sum is σ = 30708706860. Its totient is φ = 14139086976.

The previous prime is 21234252157. The next prime is 21234252223. The reversal of 21234252213 is 31225243212.

21234252213 is a `hidden beast` number, since 2 + 1 + 23 + 425 + 2 + 213 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18606869649 + 2627382564 = 136407^2 + 51258^2 .

It is not a de Polignac number, because 21234252213 - 2¹⁸ = 21233990069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234252223) 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, 1415556 + ... + 1430477.

It is an arithmetic number, because the mean of its divisors is an integer number (2559058905).

Almost surely, 2^21234252213 is an apocalyptic number.

It is an amenable number.

21234252213 is a deficient number, since it is larger than the sum of its proper divisors (9474454647).

21234252213 is a wasteful number, since it uses less digits than its factorization.

21234252213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2846868 (or 2846865 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

Adding to 21234252213 its reverse (31225243212), we get a palindrome (52459495425).

Subtracting 21234252213 from its reverse (31225243212), we obtain a palindrome (9990990999).

The spelling of 21234252213 in words is "twenty-one billion, two hundred thirty-four million, two hundred fifty-two thousand, two hundred thirteen".