21302123013 has 40 divisors (see below), whose sum is σ = 32161617048. Its totient is φ = 14050423296.

The previous prime is 21302122993. The next prime is 21302123021. The reversal of 21302123013 is 31032120312.

It can be written as a sum of positive squares in 4 ways, for example, as 3035789604 + 18266333409 = 55098^2 + 135153^2 .

It is not a de Polignac number, because 21302123013 - 2²⁶ = 21235014149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21302123053) 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 39 ways as a sum of consecutive naturals, for example, 3470295 + ... + 3476427.

Almost surely, 2^21302123013 is an apocalyptic number.

It is an amenable number.

21302123013 is a deficient number, since it is larger than the sum of its proper divisors (10859494035).

21302123013 is a wasteful number, since it uses less digits than its factorization.

21302123013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6595 (or 6586 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21302123013 its reverse (31032120312), we get a palindrome (52334243325).

The spelling of 21302123013 in words is "twenty-one billion, three hundred two million, one hundred twenty-three thousand, thirteen".