216663851 has 4 divisors (see below), whose sum is σ = 216867600. Its totient is φ = 216460104.

The previous prime is 216663829. The next prime is 216663877. The reversal of 216663851 is 158366612.

216663851 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216663851 - 2⁶ = 216663787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216663751) 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, 100271 + ... + 102408.

It is an arithmetic number, because the mean of its divisors is an integer number (54216900).

Almost surely, 2^216663851 is an apocalyptic number.

216663851 is a deficient number, since it is larger than the sum of its proper divisors (203749).

216663851 is a wasteful number, since it uses less digits than its factorization.

216663851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203748.

The product of its digits is 51840, while the sum is 38.

The square root of 216663851 is about 14719.5058001279. The cubic root of 216663851 is about 600.6140482121.

The spelling of 216663851 in words is "two hundred sixteen million, six hundred sixty-three thousand, eight hundred fifty-one".