216836441649 has 9 divisors (see below), whose sum is σ = 313210211353. Its totient is φ = 144556696452.

The previous prime is 216836441639. The next prime is 216836441663. The reversal of 216836441649 is 946144638612.

The square root of 216836441649 is 465657.

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

216836441649 is a `hidden beast` number, since 2 + 168 + 3 + 64 + 416 + 4 + 9 = 666.

216836441649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 216836441649 - 2¹⁵ = 216836408881 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216836441595 and 216836441604.

It is not an unprimeable number, because it can be changed into a prime (216836441639) 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 8 ways as a sum of consecutive naturals, for example, 1319362 + ... + 1474580.

Almost surely, 2^216836441649 is an apocalyptic number.

216836441649 is the 465657-th square number.

216836441649 is the 232829-th centered octagonal number.

It is an amenable number.

216836441649 is a deficient number, since it is larger than the sum of its proper divisors (96373769704).

216836441649 is an frugal number, since it uses more digits than its factorization.

216836441649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310444 (or 155222 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 54.

The spelling of 216836441649 in words is "two hundred sixteen billion, eight hundred thirty-six million, four hundred forty-one thousand, six hundred forty-nine".