209812 has 6 divisors (see below), whose sum is σ = 367178. Its totient is φ = 104904.

The previous prime is 209809. The next prime is 209813. The reversal of 209812 is 218902.

209812 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 171396 + 38416 = 414^2 + 196^2 .

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26223 + ... + 26230.

2²⁰⁹⁸¹² is an apocalyptic number.

It is an amenable number.

209812 is a deficient number, since it is larger than the sum of its proper divisors (157366).

209812 is a wasteful number, since it uses less digits than its factorization.

209812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52457 (or 52455 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 209812 is about 458.0523987493. The cubic root of 209812 is about 59.4214768140.

The spelling of 209812 in words is "two hundred nine thousand, eight hundred twelve".