16438055521 has 2 divisors, whose sum is σ = 16438055522. Its totient is φ = 16438055520.

The previous prime is 16438055519. The next prime is 16438055537. The reversal of 16438055521 is 12555083461.

16438055521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15340061025 + 1097994496 = 123855^2 + 33136^2 .

It is an emirp because it is prime and its reverse (12555083461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16438055521 - 2¹ = 16438055519 is a prime.

It is a super-2 number, since 2×16438055521² (a number of 21 digits) contains 22 as substring.

Together with 16438055519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (16438055321) 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, 8219027760 + 8219027761.

It is an arithmetic number, because the mean of its divisors is an integer number (8219027761).

Almost surely, 2^16438055521 is an apocalyptic number.

It is an amenable number.

16438055521 is a deficient number, since it is larger than the sum of its proper divisors (1).

16438055521 is an equidigital number, since it uses as much as digits as its factorization.

16438055521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144000, while the sum is 40.

The spelling of 16438055521 in words is "sixteen billion, four hundred thirty-eight million, fifty-five thousand, five hundred twenty-one".