165345209 has 2 divisors, whose sum is σ = 165345210. Its totient is φ = 165345208.

The previous prime is 165345161. The next prime is 165345217. The reversal of 165345209 is 902543561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145274809 + 20070400 = 12053^2 + 4480^2 .

It is an emirp because it is prime and its reverse (902543561) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165345209 is a prime.

It is not a weakly prime, because it can be changed into another prime (165345409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82672604 + 82672605.

It is an arithmetic number, because the mean of its divisors is an integer number (82672605).

Almost surely, 2^165345209 is an apocalyptic number.

It is an amenable number.

165345209 is a deficient number, since it is larger than the sum of its proper divisors (1).

165345209 is an equidigital number, since it uses as much as digits as its factorization.

165345209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 165345209 is about 12858.6627998404. The cubic root of 165345209 is about 548.8628947731.

The spelling of 165345209 in words is "one hundred sixty-five million, three hundred forty-five thousand, two hundred nine".