216623868 has 12 divisors (see below), whose sum is σ = 505455720. Its totient is φ = 72207952.

The previous prime is 216623861. The next prime is 216623917. The reversal of 216623868 is 868326612.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216623861) 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 in 3 ways as a sum of consecutive naturals, for example, 9025983 + ... + 9026006.

It is an arithmetic number, because the mean of its divisors is an integer number (42121310).

Almost surely, 2^216623868 is an apocalyptic number.

It is an amenable number.

216623868 is an abundant number, since it is smaller than the sum of its proper divisors (288831852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216623868 is a wasteful number, since it uses less digits than its factorization.

216623868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18051996 (or 18051994 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 216623868 is about 14718.1475736589. The cubic root of 216623868 is about 600.5771003030.

The spelling of 216623868 in words is "two hundred sixteen million, six hundred twenty-three thousand, eight hundred sixty-eight".