166918 has 4 divisors (see below), whose sum is σ = 250380. Its totient is φ = 83458.

The previous prime is 166909. The next prime is 166919. The reversal of 166918 is 819661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 819661 = 37 ⋅22153.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 166918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166919) by changing a digit.

166918 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41728 + ... + 41731.

It is an arithmetic number, because the mean of its divisors is an integer number (62595).

2¹⁶⁶⁹¹⁸ is an apocalyptic number.

166918 is a deficient number, since it is larger than the sum of its proper divisors (83462).

166918 is an equidigital number, since it uses as much as digits as its factorization.

166918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83461.

The product of its digits is 2592, while the sum is 31.

The square root of 166918 is about 408.5559937144. Note that the first 3 decimals coincide. The cubic root of 166918 is about 55.0597697341.

The spelling of 166918 in words is "one hundred sixty-six thousand, nine hundred eighteen".