206672209 has 4 divisors (see below), whose sum is σ = 210060340. Its totient is φ = 203284080.

The previous prime is 206672197. The next prime is 206672231. The reversal of 206672209 is 902276602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 902276602 = 2 ⋅451138301.

It can be written as a sum of positive squares in 2 ways, for example, as 2039184 + 204633025 = 1428^2 + 14305^2 .

It is a cyclic number.

It is not a de Polignac number, because 206672209 - 2⁹ = 206671697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (206672239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1693974 + ... + 1694095.

It is an arithmetic number, because the mean of its divisors is an integer number (52515085).

Almost surely, 2^206672209 is an apocalyptic number.

It is an amenable number.

206672209 is a deficient number, since it is larger than the sum of its proper divisors (3388131).

206672209 is an equidigital number, since it uses as much as digits as its factorization.

206672209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3388130.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 206672209 is about 14376.0985319384. The cubic root of 206672209 is about 591.2357599742.

The spelling of 206672209 in words is "two hundred six million, six hundred seventy-two thousand, two hundred nine".