209966 has 8 divisors (see below), whose sum is σ = 316920. Its totient is φ = 104328.

The previous prime is 209959. The next prime is 209971. The reversal of 209966 is 669902.

209966 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209966.

It is an unprimeable number.

209966 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 365 + ... + 743.

It is an arithmetic number, because the mean of its divisors is an integer number (39615).

2²⁰⁹⁹⁶⁶ is an apocalyptic number.

209966 is a deficient number, since it is larger than the sum of its proper divisors (106954).

209966 is a wasteful number, since it uses less digits than its factorization.

209966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 658.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 209966 is about 458.2204709526. The cubic root of 209966 is about 59.4360115236.

The spelling of 209966 in words is "two hundred nine thousand, nine hundred sixty-six".