216646245 has 40 divisors (see below), whose sum is σ = 395725176. Its totient is φ = 113353344.

The previous prime is 216646237. The next prime is 216646247. The reversal of 216646245 is 542646612.

216646245 is a `hidden beast` number, since 2 + 1 + 6 + 646 + 2 + 4 + 5 = 666.

216646245 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 4 ways, for example, as 39463524 + 177182721 = 6282^2 + 13311^2 .

It is not a de Polignac number, because 216646245 - 2³ = 216646237 is a prime.

It is a super-3 number, since 3×216646245³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216646247) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 16419 + ... + 26511.

Almost surely, 2^216646245 is an apocalyptic number.

It is an amenable number.

216646245 is a deficient number, since it is larger than the sum of its proper divisors (179078931).

216646245 is a wasteful number, since it uses less digits than its factorization.

216646245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10163 (or 10154 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 216646245 is about 14718.9077380083. The cubic root of 216646245 is about 600.5977792355.

The spelling of 216646245 in words is "two hundred sixteen million, six hundred forty-six thousand, two hundred forty-five".