863665009 has 2 divisors, whose sum is σ = 863665010. Its totient is φ = 863665008.

The previous prime is 863665003. The next prime is 863665013. The reversal of 863665009 is 900566368.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 862714384 + 950625 = 29372^2 + 975^2 .

It is a cyclic number.

It is not a de Polignac number, because 863665009 - 2³ = 863665001 is a prime.

It is not a weakly prime, because it can be changed into another prime (863665001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431832504 + 431832505.

It is an arithmetic number, because the mean of its divisors is an integer number (431832505).

Almost surely, 2^863665009 is an apocalyptic number.

It is an amenable number.

863665009 is a deficient number, since it is larger than the sum of its proper divisors (1).

863665009 is an equidigital number, since it uses as much as digits as its factorization.

863665009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 43.

The square root of 863665009 is about 29388.1780483241. The cubic root of 863665009 is about 952.3175215036.

The spelling of 863665009 in words is "eight hundred sixty-three million, six hundred sixty-five thousand, nine".