166789 has 4 divisors (see below), whose sum is σ = 190624. Its totient is φ = 142956.

The previous prime is 166783. The next prime is 166799. The reversal of 166789 is 987661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 987661 = 191 ⋅5171.

It is a cyclic number.

It is not a de Polignac number, because 166789 - 2³ = 166781 is a prime.

It is a plaindrome in base 10 and base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166781) 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, 11907 + ... + 11920.

It is an arithmetic number, because the mean of its divisors is an integer number (47656).

2¹⁶⁶⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

166789 is a deficient number, since it is larger than the sum of its proper divisors (23835).

166789 is an equidigital number, since it uses as much as digits as its factorization.

166789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23834.

The product of its digits is 18144, while the sum is 37.

The square root of 166789 is about 408.3980901033. The cubic root of 166789 is about 55.0455820475.

The spelling of 166789 in words is "one hundred sixty-six thousand, seven hundred eighty-nine".