216606645 has 24 divisors (see below), whose sum is σ = 381060576. Its totient is φ = 113797728.

The previous prime is 216606629. The next prime is 216606661. The reversal of 216606645 is 546606612.

It is a happy number.

216606645 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 0 + 6 + 645 = 666.

It is an interprime number because it is at equal distance from previous prime (216606629) and next prime (216606661).

It is not a de Polignac number, because 216606645 - 2⁴ = 216606629 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32907 + ... + 38936.

It is an arithmetic number, because the mean of its divisors is an integer number (15877524).

Almost surely, 2^216606645 is an apocalyptic number.

It is an amenable number.

216606645 is a deficient number, since it is larger than the sum of its proper divisors (164453931).

216606645 is a wasteful number, since it uses less digits than its factorization.

216606645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71921 (or 71918 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 216606645 is about 14717.5624680176. The cubic root of 216606645 is about 600.5611832919.

The spelling of 216606645 in words is "two hundred sixteen million, six hundred six thousand, six hundred forty-five".