168840016685 has 4 divisors (see below), whose sum is σ = 202608020028. Its totient is φ = 135072013344.

The previous prime is 168840016663. The next prime is 168840016687. The reversal of 168840016685 is 586610048861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 586610048861 = 257 ⋅2282529373.

It can be written as a sum of positive squares in 2 ways, for example, as 54431689636 + 114408327049 = 233306^2 + 338243^2 .

It is a cyclic number.

It is not a de Polignac number, because 168840016685 - 2¹⁰ = 168840015661 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 (168840016687) 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, 16884001664 + ... + 16884001673.

It is an arithmetic number, because the mean of its divisors is an integer number (50652005007).

Almost surely, 2^168840016685 is an apocalyptic number.

It is an amenable number.

168840016685 is a deficient number, since it is larger than the sum of its proper divisors (33768003343).

168840016685 is an equidigital number, since it uses as much as digits as its factorization.

168840016685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33768003342.

The product of its (nonzero) digits is 2211840, while the sum is 53.

The spelling of 168840016685 in words is "one hundred sixty-eight billion, eight hundred forty million, sixteen thousand, six hundred eighty-five".