216639688 has 16 divisors (see below), whose sum is σ = 407713500. Its totient is φ = 107916096.

The previous prime is 216639677. The next prime is 216639697. The reversal of 216639688 is 886936612.

It is a happy number.

216639688 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 216619524 + 20164 = 14718^2 + 142^2 .

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 3 ways as a sum of consecutive naturals, for example, 48183 + ... + 52486.

Almost surely, 2^216639688 is an apocalyptic number.

It is an amenable number.

216639688 is a deficient number, since it is larger than the sum of its proper divisors (191073812).

216639688 is a wasteful number, since it uses less digits than its factorization.

216639688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100944 (or 100940 counting only the distinct ones).

The product of its digits is 746496, while the sum is 49.

The square root of 216639688 is about 14718.6849956102. The cubic root of 216639688 is about 600.5917199577.

The spelling of 216639688 in words is "two hundred sixteen million, six hundred thirty-nine thousand, six hundred eighty-eight".