216539209 has 8 divisors (see below), whose sum is σ = 217895040. Its totient is φ = 215187936.

The previous prime is 216539189. The next prime is 216539221. The reversal of 216539209 is 902935612.

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 216539209 - 2⁹ = 216538697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216539009) 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, 148924 + ... + 150370.

It is an arithmetic number, because the mean of its divisors is an integer number (27236880).

Almost surely, 2^216539209 is an apocalyptic number.

It is an amenable number.

216539209 is a deficient number, since it is larger than the sum of its proper divisors (1355831).

216539209 is a wasteful number, since it uses less digits than its factorization.

216539209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2279.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 216539209 is about 14715.2712853009. The cubic root of 216539209 is about 600.4988527209.

The spelling of 216539209 in words is "two hundred sixteen million, five hundred thirty-nine thousand, two hundred nine".