166811 has 4 divisors (see below), whose sum is σ = 172224. Its totient is φ = 161400.

The previous prime is 166807. The next prime is 166823. The reversal of 166811 is 118661.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 166811 - 2² = 166807 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 166811.

It is not an unprimeable number, because it can be changed into a prime (166841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2660 + ... + 2721.

It is an arithmetic number, because the mean of its divisors is an integer number (43056).

2¹⁶⁶⁸¹¹ is an apocalyptic number.

166811 is a deficient number, since it is larger than the sum of its proper divisors (5413).

166811 is an equidigital number, since it uses as much as digits as its factorization.

166811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5412.

The product of its digits is 288, while the sum is 23.

The square root of 166811 is about 408.4250237192. The cubic root of 166811 is about 55.0480021702.

The spelling of 166811 in words is "one hundred sixty-six thousand, eight hundred eleven".