216849889 has 2 divisors, whose sum is σ = 216849890. Its totient is φ = 216849888.

The previous prime is 216849887. The next prime is 216849949. The reversal of 216849889 is 988948612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 207849889 + 9000000 = 14417^2 + 3000^2 .

It is a cyclic number.

It is not a de Polignac number, because 216849889 - 2¹ = 216849887 is a prime.

Together with 216849887, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (216849887) 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 as a sum of consecutive naturals, namely, 108424944 + 108424945.

It is an arithmetic number, because the mean of its divisors is an integer number (108424945).

Almost surely, 2^216849889 is an apocalyptic number.

It is an amenable number.

216849889 is a deficient number, since it is larger than the sum of its proper divisors (1).

216849889 is an equidigital number, since it uses as much as digits as its factorization.

216849889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1990656, while the sum is 55.

The square root of 216849889 is about 14725.8238818750. The cubic root of 216849889 is about 600.7859044003.

The spelling of 216849889 in words is "two hundred sixteen million, eight hundred forty-nine thousand, eight hundred eighty-nine".