216641728 has 28 divisors (see below), whose sum is σ = 432150520. Its totient is φ = 107753472.

The previous prime is 216641717. The next prime is 216641729. The reversal of 216641728 is 827146612.

It is not an unprimeable number, because it can be changed into a prime (216641729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3583 + ... + 21121.

Almost surely, 2^216641728 is an apocalyptic number.

It is an amenable number.

216641728 is a deficient number, since it is larger than the sum of its proper divisors (215508792).

216641728 is a wasteful number, since it uses less digits than its factorization.

216641728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17744 (or 17734 counting only the distinct ones).

The product of its digits is 32256, while the sum is 37.

The square root of 216641728 is about 14718.7542951161. The cubic root of 216641728 is about 600.5936051205.

The spelling of 216641728 in words is "two hundred sixteen million, six hundred forty-one thousand, seven hundred twenty-eight".