10206209 has 4 divisors (see below), whose sum is σ = 10991316. Its totient is φ = 9421104.

The previous prime is 10206199. The next prime is 10206257. The reversal of 10206209 is 90260201.

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 3591025 + 6615184 = 1895^2 + 2572^2 .

It is a cyclic number.

It is not a de Polignac number, because 10206209 - 2⁸ = 10205953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10206269) 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, 392534 + ... + 392559.

It is an arithmetic number, because the mean of its divisors is an integer number (2747829).

Almost surely, 2^10206209 is an apocalyptic number.

It is an amenable number.

10206209 is a deficient number, since it is larger than the sum of its proper divisors (785107).

10206209 is an equidigital number, since it uses as much as digits as its factorization.

10206209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785106.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 10206209 is about 3194.7157933062. The cubic root of 10206209 is about 216.9142844233.

The spelling of 10206209 in words is "ten million, two hundred six thousand, two hundred nine".