866603050209 has 20 divisors (see below), whose sum is σ = 1394136342676. Its totient is φ = 533294184096.

The previous prime is 866603050123. The next prime is 866603050211. The reversal of 866603050209 is 902050306668.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 109306278225 + 757296771984 = 330615^2 + 870228^2 .

It is not a de Polignac number, because 866603050209 - 2⁷ = 866603050081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (866603050219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 411491374 + ... + 411493479.

Almost surely, 2^866603050209 is an apocalyptic number.

It is an amenable number.

866603050209 is a deficient number, since it is larger than the sum of its proper divisors (527533292467).

866603050209 is a wasteful number, since it uses less digits than its factorization.

866603050209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822984878 (or 822984869 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 866603050209 in words is "eight hundred sixty-six billion, six hundred three million, fifty thousand, two hundred nine".