266865809 has 6 divisors (see below), whose sum is σ = 310435794. Its totient is φ = 228742080.

The previous prime is 266865799. The next prime is 266865817. The reversal of 266865809 is 908568662.

It can be written as a sum of positive squares in only one way, i.e., 242580625 + 24285184 = 15575^2 + 4928^2 .

It is not a de Polignac number, because 266865809 - 2⁸ = 266865553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (266865829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2723072 + ... + 2723169.

It is an arithmetic number, because the mean of its divisors is an integer number (51739299).

Almost surely, 2^266865809 is an apocalyptic number.

It is an amenable number.

266865809 is a deficient number, since it is larger than the sum of its proper divisors (43569985).

266865809 is an equidigital number, since it uses as much as digits as its factorization.

266865809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5446255 (or 5446248 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 50.

The square root of 266865809 is about 16336.0279443933. The cubic root of 266865809 is about 643.8197747099.

The spelling of 266865809 in words is "two hundred sixty-six million, eight hundred sixty-five thousand, eight hundred nine".