216606664 has 16 divisors (see below), whose sum is σ = 408865500. Its totient is φ = 107575872.

The previous prime is 216606661. The next prime is 216606667. The reversal of 216606664 is 466606612.

216606664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (216606661) and next prime (216606667).

It can be written as a sum of positive squares in 2 ways, for example, as 175774564 + 40832100 = 13258^2 + 6390^2 .

It is not an unprimeable number, because it can be changed into a prime (216606661) 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, 89667 + ... + 92050.

Almost surely, 2^216606664 is an apocalyptic number.

It is an amenable number.

216606664 is a deficient number, since it is larger than the sum of its proper divisors (192258836).

216606664 is a wasteful number, since it uses less digits than its factorization.

216606664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 181872 (or 181868 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

The square root of 216606664 is about 14717.5631135049. The cubic root of 216606664 is about 600.5612008516.

The spelling of 216606664 in words is "two hundred sixteen million, six hundred six thousand, six hundred sixty-four".