165090209 has 2 divisors, whose sum is σ = 165090210. Its totient is φ = 165090208.

The previous prime is 165090181. The next prime is 165090241. The reversal of 165090209 is 902090561.

165090209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (165090241) can be obtained adding 165090209 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109139809 + 55950400 = 10447^2 + 7480^2 .

It is a cyclic number.

It is not a de Polignac number, because 165090209 - 2¹² = 165086113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (165090269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82545104 + 82545105.

It is an arithmetic number, because the mean of its divisors is an integer number (82545105).

Almost surely, 2^165090209 is an apocalyptic number.

It is an amenable number.

165090209 is a deficient number, since it is larger than the sum of its proper divisors (1).

165090209 is an equidigital number, since it uses as much as digits as its factorization.

165090209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 165090209 is about 12848.7434794224. The cubic root of 165090209 is about 548.5805923691.

The spelling of 165090209 in words is "one hundred sixty-five million, ninety thousand, two hundred nine".