209985 has 8 divisors (see below), whose sum is σ = 336000. Its totient is φ = 111984.

The previous prime is 209983. The next prime is 209987. The reversal of 209985 is 589902.

It is an interprime number because it is at equal distance from previous prime (209983) and next prime (209987).

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

It is not a de Polignac number, because 209985 - 2¹ = 209983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6985 + ... + 7014.

It is an arithmetic number, because the mean of its divisors is an integer number (42000).

2²⁰⁹⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

209985 is a deficient number, since it is larger than the sum of its proper divisors (126015).

209985 is a wasteful number, since it uses less digits than its factorization.

209985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14007.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 209985 is about 458.2412028615. The cubic root of 209985 is about 59.4378042744.

The spelling of 209985 in words is "two hundred nine thousand, nine hundred eighty-five".