216539109 has 16 divisors (see below), whose sum is σ = 325589440. Its totient is φ = 142203600.

The previous prime is 216539101. The next prime is 216539111. The reversal of 216539109 is 901935612.

216539109 is a `hidden beast` number, since 2 + 16 + 539 + 109 = 666.

It is not a de Polignac number, because 216539109 - 2³ = 216539101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216539101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58042 + ... + 61659.

It is an arithmetic number, because the mean of its divisors is an integer number (20349340).

Almost surely, 2^216539109 is an apocalyptic number.

It is an amenable number.

216539109 is a deficient number, since it is larger than the sum of its proper divisors (109050331).

216539109 is a wasteful number, since it uses less digits than its factorization.

216539109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119777 (or 119771 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 216539109 is about 14715.2678874698. The cubic root of 216539109 is about 600.4987602821.

The spelling of 216539109 in words is "two hundred sixteen million, five hundred thirty-nine thousand, one hundred nine".