165709 has 2 divisors, whose sum is σ = 165710. Its totient is φ = 165708.

The previous prime is 165707. The next prime is 165713. The reversal of 165709 is 907561.

It is a happy number.

165709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157609 + 8100 = 397^2 + 90^2 .

It is an emirp because it is prime and its reverse (907561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165709 - 2¹ = 165707 is a prime.

Together with 165707, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82854 + 82855.

It is an arithmetic number, because the mean of its divisors is an integer number (82855).

2¹⁶⁵⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

165709 is a deficient number, since it is larger than the sum of its proper divisors (1).

165709 is an equidigital number, since it uses as much as digits as its factorization.

165709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 165709 is about 407.0737034003. The cubic root of 165709 is about 54.9265134271.

The spelling of 165709 in words is "one hundred sixty-five thousand, seven hundred nine".