168664109 has 4 divisors (see below), whose sum is σ = 168819516. Its totient is φ = 168508704.

The previous prime is 168664081. The next prime is 168664127. The reversal of 168664109 is 901466861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 901466861 = 277 ⋅3254393.

It can be written as a sum of positive squares in 2 ways, for example, as 99940009 + 68724100 = 9997^2 + 8290^2 .

It is a cyclic number.

It is not a de Polignac number, because 168664109 - 2¹² = 168660013 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 (168664009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76064 + ... + 78249.

It is an arithmetic number, because the mean of its divisors is an integer number (42204879).

Almost surely, 2^168664109 is an apocalyptic number.

It is an amenable number.

168664109 is a deficient number, since it is larger than the sum of its proper divisors (155407).

168664109 is a wasteful number, since it uses less digits than its factorization.

168664109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155406.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 168664109 is about 12987.0746898599. The cubic root of 168664109 is about 552.5109532850.

The spelling of 168664109 in words is "one hundred sixty-eight million, six hundred sixty-four thousand, one hundred nine".