216868169 has 18 divisors (see below), whose sum is σ = 256258890. Its totient is φ = 182974176.

The previous prime is 216868153. The next prime is 216868189. The reversal of 216868169 is 961868612.

216868169 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., 155950144 + 60918025 = 12488^2 + 7805^2 .

It is not a de Polignac number, because 216868169 - 2⁴ = 216868153 is a prime.

It is a super-2 number, since 2×216868169² = 94063605450825122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216868139) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 972392 + ... + 972614.

It is an arithmetic number, because the mean of its divisors is an integer number (14236605).

Almost surely, 2^216868169 is an apocalyptic number.

It is an amenable number.

216868169 is a deficient number, since it is larger than the sum of its proper divisors (39390721).

216868169 is an frugal number, since it uses more digits than its factorization.

216868169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549 (or 319 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The square root of 216868169 is about 14726.4445471404. Note that the first 3 decimals coincide. The cubic root of 216868169 is about 600.8027855983.

The spelling of 216868169 in words is "two hundred sixteen million, eight hundred sixty-eight thousand, one hundred sixty-nine".