166993 has 4 divisors (see below), whose sum is σ = 171108. Its totient is φ = 162880.

The previous prime is 166987. The next prime is 167009. The reversal of 166993 is 399661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399661 = 79 ⋅5059.

It can be written as a sum of positive squares in 2 ways, for example, as 12544 + 154449 = 112^2 + 393^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166993 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1996 + ... + 2077.

It is an arithmetic number, because the mean of its divisors is an integer number (42777).

2¹⁶⁶⁹⁹³ is an apocalyptic number.

It is an amenable number.

166993 is a deficient number, since it is larger than the sum of its proper divisors (4115).

166993 is an equidigital number, since it uses as much as digits as its factorization.

166993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4114.

The product of its digits is 8748, while the sum is 34.

The square root of 166993 is about 408.6477700906. The cubic root of 166993 is about 55.0680150290.

The spelling of 166993 in words is "one hundred sixty-six thousand, nine hundred ninety-three".