209944 has 32 divisors (see below), whose sum is σ = 472320. Its totient is φ = 85536.

The previous prime is 209939. The next prime is 209953. The reversal of 209944 is 449902.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

209944 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 7 ways as a sum of consecutive naturals, for example, 1207 + ... + 1369.

It is an arithmetic number, because the mean of its divisors is an integer number (14760).

209944 is a Friedman number, since it can be written as ((9+9)^4-4)*(2+0), using all its digits and the basic arithmetic operations.

2²⁰⁹⁹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 209944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (236160).

209944 is an abundant number, since it is smaller than the sum of its proper divisors (262376).

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

209944 is a wasteful number, since it uses less digits than its factorization.

209944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 209944 is about 458.1964644124. The cubic root of 209944 is about 59.4339355717.

The spelling of 209944 in words is "two hundred nine thousand, nine hundred forty-four".