216500866 has 24 divisors (see below), whose sum is σ = 335486340. Its totient is φ = 104772096.

The previous prime is 216500857. The next prime is 216500891. The reversal of 216500866 is 668005612.

It can be written as a sum of positive squares in 6 ways, for example, as 74390625 + 142110241 = 8625^2 + 11921^2 .

It is an unprimeable number.

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, 499786 + ... + 500218.

Almost surely, 2^216500866 is an apocalyptic number.

216500866 is a deficient number, since it is larger than the sum of its proper divisors (118985474).

216500866 is an equidigital number, since it uses as much as digits as its factorization.

216500866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 216500866 is about 14713.9683974107. The cubic root of 216500866 is about 600.4634068129.

The spelling of 216500866 in words is "two hundred sixteen million, five hundred thousand, eight hundred sixty-six".