21243404313 has 6 divisors (see below), whose sum is σ = 30684917354. Its totient is φ = 14162269536.

The previous prime is 21243404291. The next prime is 21243404321. The reversal of 21243404313 is 31340434212.

21243404313 is a `hidden beast` number, since 2 + 1 + 2 + 4 + 340 + 4 + 313 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20412408384 + 830995929 = 142872^2 + 28827^2 .

It is not a de Polignac number, because 21243404313 - 2¹³ = 21243396121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21243424313) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1180189120 + ... + 1180189137.

Almost surely, 2^21243404313 is an apocalyptic number.

It is an amenable number.

21243404313 is a deficient number, since it is larger than the sum of its proper divisors (9441513041).

21243404313 is a wasteful number, since it uses less digits than its factorization.

21243404313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2360378263 (or 2360378260 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

Adding to 21243404313 its reverse (31340434212), we get a palindrome (52583838525).

The spelling of 21243404313 in words is "twenty-one billion, two hundred forty-three million, four hundred four thousand, three hundred thirteen".