16185691729 has 27 divisors (see below), whose sum is σ = 17343971281. Its totient is φ = 15103914560.

The previous prime is 16185691727. The next prime is 16185691733. The reversal of 16185691729 is 92719658161.

It is a happy number.

The square root of 16185691729 is 127223.

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

16185691729 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 4274152129 + 11911539600 = 65377^2 + 109140^2 .

It is not a de Polignac number, because 16185691729 - 2¹ = 16185691727 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16185691729.

It is not an unprimeable number, because it can be changed into a prime (16185691723) 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 26 ways as a sum of consecutive naturals, for example, 151268094 + ... + 151268200.

Almost surely, 2^16185691729 is an apocalyptic number.

16185691729 is the 127223-rd square number.

16185691729 is the 63612-nd centered octagonal number.

It is an amenable number.

16185691729 is a deficient number, since it is larger than the sum of its proper divisors (1158279552).

16185691729 is an frugal number, since it uses more digits than its factorization.

16185691729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354 (or 177 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 55.

The spelling of 16185691729 in words is "sixteen billion, one hundred eighty-five million, six hundred ninety-one thousand, seven hundred twenty-nine".