166868639 has 8 divisors (see below), whose sum is σ = 197283360. Its totient is φ = 138098016.

The previous prime is 166868627. The next prime is 166868683. The reversal of 166868639 is 936868661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166868639 - 2⁴ = 166868623 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 (166868699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 410804 + ... + 411209.

It is an arithmetic number, because the mean of its divisors is an integer number (24660420).

Almost surely, 2^166868639 is an apocalyptic number.

166868639 is a deficient number, since it is larger than the sum of its proper divisors (30414721).

166868639 is an equidigital number, since it uses as much as digits as its factorization.

166868639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822049.

The product of its digits is 2239488, while the sum is 53.

The square root of 166868639 is about 12917.7644737780. The cubic root of 166868639 is about 550.5434177299.

It can be divided in two parts, 1668 and 68639, that added together give a palindrome (70307).

The spelling of 166868639 in words is "one hundred sixty-six million, eight hundred sixty-eight thousand, six hundred thirty-nine".