209968 has 20 divisors (see below), whose sum is σ = 444168. Its totient is φ = 95360.

The previous prime is 209959. The next prime is 209971. The reversal of 209968 is 869902.

It is a super-2 number, since 2×209968² = 88173122048, which contains 22 as substring.

It is an unprimeable number.

209968 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 421 + ... + 772.

2²⁰⁹⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

209968 is an abundant number, since it is smaller than the sum of its proper divisors (234200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

209968 is a wasteful number, since it uses less digits than its factorization.

209968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1212 (or 1206 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 209968 is about 458.2226533030. Note that the first 3 decimals coincide. The cubic root of 209968 is about 59.4362002393.

The spelling of 209968 in words is "two hundred nine thousand, nine hundred sixty-eight".