165395809 has 8 divisors (see below), whose sum is σ = 170811368. Its totient is φ = 160030080.

The previous prime is 165395803. The next prime is 165395833. The reversal of 165395809 is 908593561.

It can be written as a sum of positive squares in 4 ways, for example, as 45427600 + 119968209 = 6740^2 + 10953^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165395809 - 2⁵ = 165395777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165395803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5652 + ... + 19045.

It is an arithmetic number, because the mean of its divisors is an integer number (21351421).

Almost surely, 2^165395809 is an apocalyptic number.

It is an amenable number.

165395809 is a deficient number, since it is larger than the sum of its proper divisors (5415559).

165395809 is a wasteful number, since it uses less digits than its factorization.

165395809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24915.

The product of its (nonzero) digits is 291600, while the sum is 46.

The square root of 165395809 is about 12860.6301945122. The cubic root of 165395809 is about 548.9188779090.

The spelling of 165395809 in words is "one hundred sixty-five million, three hundred ninety-five thousand, eight hundred nine".