209085165 has 16 divisors (see below), whose sum is σ = 371707200. Its totient is φ = 111512016.

The previous prime is 209085133. The next prime is 209085179. The reversal of 209085165 is 561580902.

It is a happy number.

It is not a de Polignac number, because 209085165 - 2⁵ = 209085133 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 774255 + ... + 774524.

It is an arithmetic number, because the mean of its divisors is an integer number (23231700).

Almost surely, 2^209085165 is an apocalyptic number.

It is an amenable number.

209085165 is a deficient number, since it is larger than the sum of its proper divisors (162622035).

209085165 is a wasteful number, since it uses less digits than its factorization.

209085165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1548793 (or 1548787 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 209085165 is about 14459.7774879145. Note that the first 3 decimals coincide. The cubic root of 209085165 is about 593.5278106406.

It can be divided in two parts, 2090851 and 65, that added together give a square (2090916 = 1446²).

The spelling of 209085165 in words is "two hundred nine million, eighty-five thousand, one hundred sixty-five".