16809985 has 8 divisors (see below), whose sum is σ = 20514240. Its totient is φ = 13219824.

The previous prime is 16809979. The next prime is 16809997. The reversal of 16809985 is 58990861.

16809985 is nontrivially palindromic in base 16.

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 16809985 - 2³ = 16809977 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28197 + ... + 28786.

It is an arithmetic number, because the mean of its divisors is an integer number (2564280).

It is a Proth number, since it is equal to 513 ⋅ 2¹⁵ + 1 and 513 < 2¹⁵.

Almost surely, 2^16809985 is an apocalyptic number.

It is an amenable number.

16809985 is a deficient number, since it is larger than the sum of its proper divisors (3704255).

16809985 is an equidigital number, since it uses as much as digits as its factorization.

16809985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57047.

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 16809985 is about 4099.9981707313. The cubic root of 16809985 is about 256.1665633570.

The spelling of 16809985 in words is "sixteen million, eight hundred nine thousand, nine hundred eighty-five".