216989845 has 12 divisors (see below), whose sum is σ = 264137580. Its totient is φ = 171127040.

The previous prime is 216989837. The next prime is 216989849. The reversal of 216989845 is 548989612.

It can be written as a sum of positive squares in 2 ways, for example, as 64368529 + 152621316 = 8023^2 + 12354^2 .

It is not a de Polignac number, because 216989845 - 2³ = 216989837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216989792 and 216989801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216989849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20901 + ... + 29509.

It is an arithmetic number, because the mean of its divisors is an integer number (22011465).

Almost surely, 2^216989845 is an apocalyptic number.

It is an amenable number.

216989845 is a deficient number, since it is larger than the sum of its proper divisors (47147735).

216989845 is an frugal number, since it uses more digits than its factorization.

216989845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8756 (or 8685 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 52.

The square root of 216989845 is about 14730.5751754641. The cubic root of 216989845 is about 600.9151266771.

The spelling of 216989845 in words is "two hundred sixteen million, nine hundred eighty-nine thousand, eight hundred forty-five".