166191 has 8 divisors (see below), whose sum is σ = 228864. Its totient is φ = 107160.

The previous prime is 166189. The next prime is 166207. The reversal of 166191 is 191661.

166191 = T₄₀ + T₄₁ + ... + T₁₀₁.

166191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166191 - 2¹ = 166189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166151) 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, 801 + ... + 986.

It is an arithmetic number, because the mean of its divisors is an integer number (28608).

2¹⁶⁶¹⁹¹ is an apocalyptic number.

166191 is a deficient number, since it is larger than the sum of its proper divisors (62673).

166191 is a wasteful number, since it uses less digits than its factorization.

166191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1821.

The product of its digits is 324, while the sum is 24.

The square root of 166191 is about 407.6653038952. The cubic root of 166191 is about 54.9797170389.

It can be divided in two parts, 1661 and 91, that multiplied together give a palindrome (151151).

The spelling of 166191 in words is "one hundred sixty-six thousand, one hundred ninety-one".