165789 has 18 divisors (see below), whose sum is σ = 261690. Its totient is φ = 101088.

The previous prime is 165779. The next prime is 165799. The reversal of 165789 is 987561.

165789 = 67² + 68² + ... + 92².

It is an interprime number because it is at equal distance from previous prime (165779) and next prime (165799).

It can be written as a sum of positive squares in 3 ways, for example, as 1764 + 164025 = 42^2 + 405^2 .

It is not a de Polignac number, because 165789 - 2⁸ = 165533 is a prime.

It is a Curzon number.

It is a congruent number.

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 17 ways as a sum of consecutive naturals, for example, 1467 + ... + 1575.

2¹⁶⁵⁷⁸⁹ is an apocalyptic number.

165789 is the 218-th nonagonal number.

It is an amenable number.

165789 is a deficient number, since it is larger than the sum of its proper divisors (95901).

165789 is a wasteful number, since it uses less digits than its factorization.

165789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141 (or 125 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 165789 is about 407.1719538475. The cubic root of 165789 is about 54.9353510363.

The spelling of 165789 in words is "one hundred sixty-five thousand, seven hundred eighty-nine".