21304043513 has 2 divisors, whose sum is σ = 21304043514. Its totient is φ = 21304043512.

The previous prime is 21304043489. The next prime is 21304043587. The reversal of 21304043513 is 31534040312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21230821264 + 73222249 = 145708^2 + 8557^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21304043513 is a prime.

It is not a weakly prime, because it can be changed into another prime (21309043513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652021756 + 10652021757.

It is an arithmetic number, because the mean of its divisors is an integer number (10652021757).

Almost surely, 2^21304043513 is an apocalyptic number.

It is an amenable number.

21304043513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21304043513 is an equidigital number, since it uses as much as digits as its factorization.

21304043513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 21304043513 its reverse (31534040312), we get a palindrome (52838083825).

The spelling of 21304043513 in words is "twenty-one billion, three hundred four million, forty-three thousand, five hundred thirteen".