16521760369 has 9 divisors (see below), whose sum is σ = 17553118881. Its totient is φ = 15547835520.

The previous prime is 16521760357. The next prime is 16521760393. The reversal of 16521760369 is 96306712561.

The square root of 16521760369 is 128537.

It is a perfect power (a square), and thus also a powerful number.

16521760369 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6426225 + 16515334144 = 2535^2 + 128512^2 .

It is not a de Polignac number, because 16521760369 - 2⁹ = 16521759857 is a prime.

It is a super-2 number, since 2×16521760369² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16521760349) 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 in 8 ways as a sum of consecutive naturals, for example, 2181349 + ... + 2188909.

Almost surely, 2^16521760369 is an apocalyptic number.

16521760369 is the 128537-th square number.

16521760369 is the 64269-th centered octagonal number.

It is an amenable number.

16521760369 is a deficient number, since it is larger than the sum of its proper divisors (1031358512).

16521760369 is an frugal number, since it uses more digits than its factorization.

16521760369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15156 (or 7578 counting only the distinct ones).

The product of its (nonzero) digits is 408240, while the sum is 46.

The spelling of 16521760369 in words is "sixteen billion, five hundred twenty-one million, seven hundred sixty thousand, three hundred sixty-nine".