209668 has 24 divisors (see below), whose sum is σ = 399168. Its totient is φ = 96096.

The previous prime is 209659. The next prime is 209669. The reversal of 209668 is 866902.

It is an Ulam number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (209669) 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, 3930 + ... + 3982.

It is an arithmetic number, because the mean of its divisors is an integer number (16632).

2²⁰⁹⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

209668 is a deficient number, since it is larger than the sum of its proper divisors (189500).

209668 is a wasteful number, since it uses less digits than its factorization.

209668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 209668 is about 457.8951845128. The cubic root of 209668 is about 59.4078794809.

The spelling of 209668 in words is "two hundred nine thousand, six hundred sixty-eight".