206669 has 4 divisors (see below), whose sum is σ = 218844. Its totient is φ = 194496.

The previous prime is 206651. The next prime is 206699. The reversal of 206669 is 966602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75625 + 131044 = 275^2 + 362^2 .

It is a cyclic number.

It is not a de Polignac number, because 206669 - 2⁸ = 206413 is a prime.

It is a super-2 number, since 2×206669² = 85424151122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206639) 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, 6062 + ... + 6095.

It is an arithmetic number, because the mean of its divisors is an integer number (54711).

2²⁰⁶⁶⁶⁹ is an apocalyptic number.

It is an amenable number.

206669 is a deficient number, since it is larger than the sum of its proper divisors (12175).

206669 is a wasteful number, since it uses less digits than its factorization.

206669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12174.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 206669 is about 454.6086228835. The cubic root of 206669 is about 59.1232699919.

The spelling of 206669 in words is "two hundred six thousand, six hundred sixty-nine".