21523435213 has 32 divisors (see below), whose sum is σ = 26033356800. Its totient is φ = 17395874496.

The previous prime is 21523435211. The next prime is 21523435217. The reversal of 21523435213 is 31253432512.

It is not a de Polignac number, because 21523435213 - 2¹ = 21523435211 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 (21523435211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13595820 + ... + 13597402.

It is an arithmetic number, because the mean of its divisors is an integer number (813542400).

Almost surely, 2^21523435213 is an apocalyptic number.

21523435213 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21523435213 is a deficient number, since it is larger than the sum of its proper divisors (4509921587).

21523435213 is a wasteful number, since it uses less digits than its factorization.

21523435213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2761.

The product of its digits is 21600, while the sum is 31.

Adding to 21523435213 its reverse (31253432512), we get a palindrome (52776867725).

The spelling of 21523435213 in words is "twenty-one billion, five hundred twenty-three million, four hundred thirty-five thousand, two hundred thirteen".