209973 has 4 divisors (see below), whose sum is σ = 279968. Its totient is φ = 139980.

The previous prime is 209971. The next prime is 209977. The reversal of 209973 is 379902.

209973 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 209973 - 2¹ = 209971 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 209973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34993 + ... + 34998.

It is an arithmetic number, because the mean of its divisors is an integer number (69992).

2²⁰⁹⁹⁷³ is an apocalyptic number.

It is an amenable number.

209973 is a deficient number, since it is larger than the sum of its proper divisors (69995).

209973 is an equidigital number, since it uses as much as digits as its factorization.

209973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69994.

The product of its (nonzero) digits is 3402, while the sum is 30.

The square root of 209973 is about 458.2281091334. The cubic root of 209973 is about 59.4366720233.

The spelling of 209973 in words is "two hundred nine thousand, nine hundred seventy-three".