216389641329 has 27 divisors (see below), whose sum is σ = 329919741099. Its totient is φ = 136650395520.

The previous prime is 216389641297. The next prime is 216389641333. The reversal of 216389641329 is 923146983612.

The square root of 216389641329 is 465177.

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

216389641329 is a `hidden beast` number, since 216 + 3 + 8 + 9 + 6 + 413 + 2 + 9 = 666.

216389641329 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 only one way, i.e., 79962831729 + 136426809600 = 282777^2 + 369360^2 .

It is not a de Polignac number, because 216389641329 - 2⁵ = 216389641297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216389641129) 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 in 26 ways as a sum of consecutive naturals, for example, 26511009 + ... + 26519169.

Almost surely, 2^216389641329 is an apocalyptic number.

216389641329 is the 465177-th square number.

216389641329 is the 232589-th centered octagonal number.

It is an amenable number.

216389641329 is a deficient number, since it is larger than the sum of its proper divisors (113530099770).

216389641329 is an frugal number, since it uses more digits than its factorization.

216389641329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16366 (or 8183 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

It can be divided in two parts, 2163896 and 41329, that added together give a square (2205225 = 1485²).

The spelling of 216389641329 in words is "two hundred sixteen billion, three hundred eighty-nine million, six hundred forty-one thousand, three hundred twenty-nine".