216873309 has 8 divisors (see below), whose sum is σ = 289234080. Its totient is φ = 144547376.

The previous prime is 216873299. The next prime is 216873311. The reversal of 216873309 is 903378612.

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 216873309 - 2¹⁵ = 216840541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216873359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15187 + ... + 25775.

It is an arithmetic number, because the mean of its divisors is an integer number (36154260).

Almost surely, 2^216873309 is an apocalyptic number.

It is an amenable number.

216873309 is a deficient number, since it is larger than the sum of its proper divisors (72360771).

216873309 is a wasteful number, since it uses less digits than its factorization.

216873309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17419.

The product of its (nonzero) digits is 54432, while the sum is 39.

The square root of 216873309 is about 14726.6190620930. The cubic root of 216873309 is about 600.8075321100.

The spelling of 216873309 in words is "two hundred sixteen million, eight hundred seventy-three thousand, three hundred nine".