21012320313 has 12 divisors (see below), whose sum is σ = 31171430628. Its totient is φ = 13629612960.

The previous prime is 21012320261. The next prime is 21012320317. The reversal of 21012320313 is 31302321012.

21012320313 is a `hidden beast` number, since 21 + 0 + 12 + 320 + 313 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 10529222544 + 10483097769 = 102612^2 + 102387^2 .

It is not a de Polignac number, because 21012320313 - 2¹⁸ = 21012058169 is a prime.

It is a super-2 number, since 2×21012320313² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21012320317) 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, 31549698 + ... + 31550363.

It is an arithmetic number, because the mean of its divisors is an integer number (2597619219).

Almost surely, 2^21012320313 is an apocalyptic number.

It is an amenable number.

21012320313 is a deficient number, since it is larger than the sum of its proper divisors (10159110315).

21012320313 is a wasteful number, since it uses less digits than its factorization.

21012320313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63100104 (or 63100101 counting only the distinct ones).

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

Adding to 21012320313 its reverse (31302321012), we get a palindrome (52314641325).

The spelling of 21012320313 in words is "twenty-one billion, twelve million, three hundred twenty thousand, three hundred thirteen".