216634809 has 8 divisors (see below), whose sum is σ = 289971360. Its totient is φ = 143860736.

The previous prime is 216634787. The next prime is 216634819. The reversal of 216634809 is 908436612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216634809 - 2⁵ = 216634777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216634819) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 139719 + ... + 141260.

It is an arithmetic number, because the mean of its divisors is an integer number (36246420).

Almost surely, 2^216634809 is an apocalyptic number.

It is an amenable number.

216634809 is a deficient number, since it is larger than the sum of its proper divisors (73336551).

216634809 is a wasteful number, since it uses less digits than its factorization.

216634809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281239.

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 216634809 is about 14718.5192529684. The cubic root of 216634809 is about 600.5872112286.

The spelling of 216634809 in words is "two hundred sixteen million, six hundred thirty-four thousand, eight hundred nine".