166321 has 4 divisors (see below), whose sum is σ = 169200.
Its totient is φ = 163444.
The previous prime is 166319. The next prime is 166349. The reversal of 166321 is 123661.
Adding to 166321 its reverse (123661), we get a palindrome (289982).
166321 is nontrivially palindromic in base 7.
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.
It is a cyclic number.
It is not a de Polignac number, because 166321 - 21 = 166319 is a prime.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (166301) 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, 1351 + ... + 1468.
It is an arithmetic number, because the mean of its divisors is an integer number (42300).
2166321 is an apocalyptic number.
It is an amenable number.
166321 is a deficient number, since it is larger than the sum of its proper divisors (2879).
166321 is an equidigital number, since it uses as much as digits as its factorization.
166321 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2878.
The product of its digits is 216, while the sum is 19.
The square root of 166321 is about 407.8247172499.
The cubic root of 166321 is about 54.9940489429.
The spelling of 166321 in words is "one hundred sixty-six thousand, three hundred twenty-one".