201209165 has 4 divisors (see below), whose sum is σ = 241451004. Its totient is φ = 160967328.

The previous prime is 201209143. The next prime is 201209167. The reversal of 201209165 is 561902102.

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 52027369 + 149181796 = 7213^2 + 12214^2 .

It is a cyclic number.

It is not a de Polignac number, because 201209165 - 2²⁰ = 200160589 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 (201209167) 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, 20120912 + ... + 20120921.

It is an arithmetic number, because the mean of its divisors is an integer number (60362751).

Almost surely, 2^201209165 is an apocalyptic number.

It is an amenable number.

201209165 is a deficient number, since it is larger than the sum of its proper divisors (40241839).

201209165 is an equidigital number, since it uses as much as digits as its factorization.

201209165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40241838.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 201209165 is about 14184.8216414589. The cubic root of 201209165 is about 585.9797204753.

The spelling of 201209165 in words is "two hundred one million, two hundred nine thousand, one hundred sixty-five".