166805 has 8 divisors (see below), whose sum is σ = 203352. Its totient is φ = 131328.

The previous prime is 166799. The next prime is 166807. The reversal of 166805 is 508661.

166805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 47089 + 119716 = 217^2 + 346^2 .

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 166805 - 2⁶ = 166741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137 + ... + 593.

It is an arithmetic number, because the mean of its divisors is an integer number (25419).

2¹⁶⁶⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

166805 is a deficient number, since it is larger than the sum of its proper divisors (36547).

166805 is an equidigital number, since it uses as much as digits as its factorization.

166805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 535.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 166805 is about 408.4176783637. The cubic root of 166805 is about 55.0473421579.

The spelling of 166805 in words is "one hundred sixty-six thousand, eight hundred five".