21144326513 has 2 divisors, whose sum is σ = 21144326514. Its totient is φ = 21144326512.

The previous prime is 21144326507. The next prime is 21144326531. The reversal of 21144326513 is 31562344112.

Together with next prime (21144326531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14197437409 + 6946889104 = 119153^2 + 83348^2 .

It is a cyclic number.

It is not a de Polignac number, because 21144326513 - 2¹⁴ = 21144310129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21144326513.

It is not a weakly prime, because it can be changed into another prime (21144326543) 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 as a sum of consecutive naturals, namely, 10572163256 + 10572163257.

It is an arithmetic number, because the mean of its divisors is an integer number (10572163257).

Almost surely, 2^21144326513 is an apocalyptic number.

It is an amenable number.

21144326513 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144326513 is an equidigital number, since it uses as much as digits as its factorization.

21144326513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

The spelling of 21144326513 in words is "twenty-one billion, one hundred forty-four million, three hundred twenty-six thousand, five hundred thirteen".