165739 has 4 divisors (see below), whose sum is σ = 189424. Its totient is φ = 142056.

The previous prime is 165721. The next prime is 165749. The reversal of 165739 is 937561.

165739 is nontrivially palindromic in base 12.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 937561 = 113 ⋅8297.

It is a cyclic number.

It is not a de Polignac number, because 165739 - 2⁵ = 165707 is a prime.

It is a super-2 number, since 2×165739² = 54938832242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165739.

It is not an unprimeable number, because it can be changed into a prime (165709) 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, 11832 + ... + 11845.

It is an arithmetic number, because the mean of its divisors is an integer number (47356).

2¹⁶⁵⁷³⁹ is an apocalyptic number.

165739 is a deficient number, since it is larger than the sum of its proper divisors (23685).

165739 is an equidigital number, since it uses as much as digits as its factorization.

165739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23684.

The product of its digits is 5670, while the sum is 31.

The square root of 165739 is about 407.1105500967. The cubic root of 165739 is about 54.9298278638.

The spelling of 165739 in words is "one hundred sixty-five thousand, seven hundred thirty-nine".