166001 has 4 divisors (see below), whose sum is σ = 181104. Its totient is φ = 150900.

The previous prime is 165983. The next prime is 166013. The reversal of 166001 is 100661.

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: 100661 = 11 ⋅9151.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166021) 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, 7535 + ... + 7556.

It is an arithmetic number, because the mean of its divisors is an integer number (45276).

2¹⁶⁶⁰⁰¹ is an apocalyptic number.

166001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166001 is a deficient number, since it is larger than the sum of its proper divisors (15103).

166001 is a wasteful number, since it uses less digits than its factorization.

166001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15102.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 166001 is about 407.4322029492. The cubic root of 166001 is about 54.9587569595.

Adding to 166001 its reverse (100661), we get a palindrome (266662).

The spelling of 166001 in words is "one hundred sixty-six thousand, one".