166401223 has 4 divisors (see below), whose sum is σ = 166427800. Its totient is φ = 166374648.

The previous prime is 166401199. The next prime is 166401239. The reversal of 166401223 is 322104661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 166401223 - 2²¹ = 164304071 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 (166401293) 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, 1861 + ... + 18337.

It is an arithmetic number, because the mean of its divisors is an integer number (41606950).

Almost surely, 2^166401223 is an apocalyptic number.

166401223 is a deficient number, since it is larger than the sum of its proper divisors (26577).

166401223 is a wasteful number, since it uses less digits than its factorization.

166401223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26576.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 166401223 is about 12899.6598017157. The cubic root of 166401223 is about 550.0288943498.

Adding to 166401223 its reverse (322104661), we get a palindrome (488505884).

The spelling of 166401223 in words is "one hundred sixty-six million, four hundred one thousand, two hundred twenty-three".