216545173 has 4 divisors (see below), whose sum is σ = 233202508. Its totient is φ = 199887840.

The previous prime is 216545159. The next prime is 216545179. The reversal of 216545173 is 371545612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9847044 + 206698129 = 3138^2 + 14377^2 .

It is a cyclic number.

It is not a de Polignac number, because 216545173 - 2⁵ = 216545141 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 (216545179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8328648 + ... + 8328673.

It is an arithmetic number, because the mean of its divisors is an integer number (58300627).

Almost surely, 2^216545173 is an apocalyptic number.

It is an amenable number.

216545173 is a deficient number, since it is larger than the sum of its proper divisors (16657335).

216545173 is a wasteful number, since it uses less digits than its factorization.

216545173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16657334.

The product of its digits is 25200, while the sum is 34.

The square root of 216545173 is about 14715.4739305263. The cubic root of 216545173 is about 600.5043657214.

The spelling of 216545173 in words is "two hundred sixteen million, five hundred forty-five thousand, one hundred seventy-three".