206705 has 4 divisors (see below), whose sum is σ = 248052. Its totient is φ = 165360.

The previous prime is 206699. The next prime is 206749. The reversal of 206705 is 507602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507602 = 2 ⋅253801.

It can be written as a sum of positive squares in 2 ways, for example, as 53824 + 152881 = 232^2 + 391^2 .

It is not a de Polignac number, because 206705 - 2⁶ = 206641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20666 + ... + 20675.

It is an arithmetic number, because the mean of its divisors is an integer number (62013).

2²⁰⁶⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

206705 is a deficient number, since it is larger than the sum of its proper divisors (41347).

206705 is an equidigital number, since it uses as much as digits as its factorization.

206705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41346.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 206705 is about 454.6482156569. The cubic root of 206705 is about 59.1267027179.

The spelling of 206705 in words is "two hundred six thousand, seven hundred five".