21303312013 has 2 divisors, whose sum is σ = 21303312014. Its totient is φ = 21303312012.

The previous prime is 21303311989. The next prime is 21303312047. The reversal of 21303312013 is 31021330312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20644517124 + 658794889 = 143682^2 + 25667^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303312013 - 2¹³ = 21303303821 is a prime.

It is a super-2 number, since 2×21303312013² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303319013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651656006 + 10651656007.

It is an arithmetic number, because the mean of its divisors is an integer number (10651656007).

Almost surely, 2^21303312013 is an apocalyptic number.

It is an amenable number.

21303312013 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303312013 is an equidigital number, since it uses as much as digits as its factorization.

21303312013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21303312013 its reverse (31021330312), we get a palindrome (52324642325).

The spelling of 21303312013 in words is "twenty-one billion, three hundred three million, three hundred twelve thousand, thirteen".