165973 has 4 divisors (see below), whose sum is σ = 166860. Its totient is φ = 165088.

The previous prime is 165961. The next prime is 165983. The reversal of 165973 is 379561.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7569 + 158404 = 87^2 + 398^2 .

It is a cyclic number.

It is not a de Polignac number, because 165973 - 2⁵ = 165941 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

165973 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40 + ... + 577.

It is an arithmetic number, because the mean of its divisors is an integer number (41715).

2¹⁶⁵⁹⁷³ is an apocalyptic number.

It is an amenable number.

165973 is a deficient number, since it is larger than the sum of its proper divisors (887).

165973 is an equidigital number, since it uses as much as digits as its factorization.

165973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886.

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

The square root of 165973 is about 407.3978399550. The cubic root of 165973 is about 54.9556667537.

The spelling of 165973 in words is "one hundred sixty-five thousand, nine hundred seventy-three".