181166 has 4 divisors (see below), whose sum is σ = 271752. Its totient is φ = 90582.

The previous prime is 181157. The next prime is 181183. The reversal of 181166 is 661181.

It is a happy number.

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

It is a super-2 number, since 2×181166² = 65642239112, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45290 + ... + 45293.

It is an arithmetic number, because the mean of its divisors is an integer number (67938).

2¹⁸¹¹⁶⁶ is an apocalyptic number.

181166 is a deficient number, since it is larger than the sum of its proper divisors (90586).

181166 is an equidigital number, since it uses as much as digits as its factorization.

181166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90585.

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

The square root of 181166 is about 425.6359947185. The cubic root of 181166 is about 56.5838158725.

The spelling of 181166 in words is "one hundred eighty-one thousand, one hundred sixty-six".