216385992 has 40 divisors (see below), whose sum is σ = 606082950. Its totient is φ = 72128448.

The previous prime is 216385969. The next prime is 216385997. The reversal of 216385992 is 299583612.

216385992 is a `hidden beast` number, since 2 + 1 + 638 + 5 + 9 + 9 + 2 = 666.

216385992 is digitally balanced in base 2, 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 only one way, i.e., 214153956 + 2232036 = 14634^2 + 1494^2 .

It is not an unprimeable number, because it can be changed into a prime (216385997) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 166317 + ... + 167612.

Almost surely, 2^216385992 is an apocalyptic number.

It is an amenable number.

216385992 is an abundant number, since it is smaller than the sum of its proper divisors (389696958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216385992 is a wasteful number, since it uses less digits than its factorization.

216385992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333947 (or 333934 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 216385992 is about 14710.0643098526. The cubic root of 216385992 is about 600.3571873198.

The spelling of 216385992 in words is "two hundred sixteen million, three hundred eighty-five thousand, nine hundred ninety-two".