216399688 has 16 divisors (see below), whose sum is σ = 405981360. Its totient is φ = 108138000.

The previous prime is 216399661. The next prime is 216399691. The reversal of 216399688 is 886993612.

It is a happy number.

It is an unprimeable number.

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, 9363 + ... + 22813.

It is an arithmetic number, because the mean of its divisors is an integer number (25373835).

Almost surely, 2^216399688 is an apocalyptic number.

It is an amenable number.

216399688 is a deficient number, since it is larger than the sum of its proper divisors (189581672).

216399688 is a wasteful number, since it uses less digits than its factorization.

216399688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15468 (or 15464 counting only the distinct ones).

The product of its digits is 1119744, while the sum is 52.

The square root of 216399688 is about 14710.5298341018. The cubic root of 216399688 is about 600.3698534487.

The spelling of 216399688 in words is "two hundred sixteen million, three hundred ninety-nine thousand, six hundred eighty-eight".