166555 has 4 divisors (see below), whose sum is σ = 199872. Its totient is φ = 133240.

The previous prime is 166541. The next prime is 166561. The reversal of 166555 is 555661.

166555 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 166555 - 2⁹ = 166043 is a prime.

It is a Duffinian number.

166555 is a lucky number.

It is a plaindrome in base 14.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16651 + ... + 16660.

It is an arithmetic number, because the mean of its divisors is an integer number (49968).

2¹⁶⁶⁵⁵⁵ is an apocalyptic number.

166555 is a deficient number, since it is larger than the sum of its proper divisors (33317).

166555 is an equidigital number, since it uses as much as digits as its factorization.

166555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33316.

The product of its digits is 4500, while the sum is 28.

The square root of 166555 is about 408.1115043710. Note that the first 3 decimals coincide. The cubic root of 166555 is about 55.0198275620.

The spelling of 166555 in words is "one hundred sixty-six thousand, five hundred fifty-five".