168478921 has 8 divisors (see below), whose sum is σ = 181669824. Its totient is φ = 155321040.

The previous prime is 168478913. The next prime is 168478927. The reversal of 168478921 is 129874861.

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

It is a cyclic number.

It is not a de Polignac number, because 168478921 - 2³ = 168478913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168478927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2916 + ... + 18586.

It is an arithmetic number, because the mean of its divisors is an integer number (22708728).

Almost surely, 2^168478921 is an apocalyptic number.

It is an amenable number.

168478921 is a deficient number, since it is larger than the sum of its proper divisors (13190903).

168478921 is a wasteful number, since it uses less digits than its factorization.

168478921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16511.

The product of its digits is 193536, while the sum is 46.

The square root of 168478921 is about 12979.9430276099. The cubic root of 168478921 is about 552.3086658919.

The spelling of 168478921 in words is "one hundred sixty-eight million, four hundred seventy-eight thousand, nine hundred twenty-one".