16445648689 has 2 divisors, whose sum is σ = 16445648690. Its totient is φ = 16445648688.

The previous prime is 16445648677. The next prime is 16445648767. The reversal of 16445648689 is 98684654461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15274982464 + 1170666225 = 123592^2 + 34215^2 .

It is an emirp because it is prime and its reverse (98684654461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16445648689 - 2¹¹ = 16445646641 is a prime.

It is not a weakly prime, because it can be changed into another prime (16445648789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8222824344 + 8222824345.

It is an arithmetic number, because the mean of its divisors is an integer number (8222824345).

Almost surely, 2^16445648689 is an apocalyptic number.

It is an amenable number.

16445648689 is a deficient number, since it is larger than the sum of its proper divisors (1).

16445648689 is an equidigital number, since it uses as much as digits as its factorization.

16445648689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39813120, while the sum is 61.

The spelling of 16445648689 in words is "sixteen billion, four hundred forty-five million, six hundred forty-eight thousand, six hundred eighty-nine".