166291 has 4 divisors (see below), whose sum is σ = 167400. Its totient is φ = 165184.

The previous prime is 166289. The next prime is 166297. The reversal of 166291 is 192661.

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 is a cyclic number.

It is not a de Polignac number, because 166291 - 2¹ = 166289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166297) 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, 286 + ... + 643.

It is an arithmetic number, because the mean of its divisors is an integer number (41850).

2¹⁶⁶²⁹¹ is an apocalyptic number.

166291 is a deficient number, since it is larger than the sum of its proper divisors (1109).

166291 is an equidigital number, since it uses as much as digits as its factorization.

166291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108.

The product of its digits is 648, while the sum is 25.

The square root of 166291 is about 407.7879350839. The cubic root of 166291 is about 54.9907422434.

The spelling of 166291 in words is "one hundred sixty-six thousand, two hundred ninety-one".