166621323 has 16 divisors (see below), whose sum is σ = 248910336. Its totient is φ = 98252640.

The previous prime is 166621291. The next prime is 166621337. The reversal of 166621323 is 323126661.

It is not a de Polignac number, because 166621323 - 2⁵ = 166621291 is a prime.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (166621423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67011 + ... + 69452.

It is an arithmetic number, because the mean of its divisors is an integer number (15556896).

Almost surely, 2^166621323 is an apocalyptic number.

166621323 is a deficient number, since it is larger than the sum of its proper divisors (82289013).

166621323 is a wasteful number, since it uses less digits than its factorization.

166621323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136514.

The product of its digits is 7776, while the sum is 30.

The square root of 166621323 is about 12908.1882152376. The cubic root of 166621323 is about 550.2712964596.

Adding to 166621323 its reverse (323126661), we get a palindrome (489747984).

The spelling of 166621323 in words is "one hundred sixty-six million, six hundred twenty-one thousand, three hundred twenty-three".