213709 has 4 divisors (see below), whose sum is σ = 218304. Its totient is φ = 209116.

The previous prime is 213659. The next prime is 213713. The reversal of 213709 is 907312.

213709 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 a cyclic number.

It is not a de Polignac number, because 213709 - 2¹¹ = 211661 is a prime.

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 213709.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213799) 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, 2227 + ... + 2320.

It is an arithmetic number, because the mean of its divisors is an integer number (54576).

2²¹³⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

213709 is a deficient number, since it is larger than the sum of its proper divisors (4595).

213709 is an equidigital number, since it uses as much as digits as its factorization.

213709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4594.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 213709 is about 462.2867075744. The cubic root of 213709 is about 59.7871159366.

The spelling of 213709 in words is "two hundred thirteen thousand, seven hundred nine".