216209 has 8 divisors (see below), whose sum is σ = 251328. Its totient is φ = 182160.

The previous prime is 216179. The next prime is 216211. The reversal of 216209 is 902612.

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 216209 - 2⁸ = 215953 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (216259) 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, 239 + ... + 699.

It is an arithmetic number, because the mean of its divisors is an integer number (31416).

2²¹⁶²⁰⁹ is an apocalyptic number.

It is an amenable number.

216209 is a deficient number, since it is larger than the sum of its proper divisors (35119).

216209 is an equidigital number, since it uses as much as digits as its factorization.

216209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 216209 is about 464.9827953806. The cubic root of 216209 is about 60.0193456136.

The spelling of 216209 in words is "two hundred sixteen thousand, two hundred nine".