865206817 has 2 divisors, whose sum is σ = 865206818. Its totient is φ = 865206816.

The previous prime is 865206809. The next prime is 865206863. The reversal of 865206817 is 718602568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 526977936 + 338228881 = 22956^2 + 18391^2 .

It is a cyclic number.

It is not a de Polignac number, because 865206817 - 2³ = 865206809 is a prime.

It is not a weakly prime, because it can be changed into another prime (865206217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432603408 + 432603409.

It is an arithmetic number, because the mean of its divisors is an integer number (432603409).

Almost surely, 2^865206817 is an apocalyptic number.

It is an amenable number.

865206817 is a deficient number, since it is larger than the sum of its proper divisors (1).

865206817 is an equidigital number, since it uses as much as digits as its factorization.

865206817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 161280, while the sum is 43.

The square root of 865206817 is about 29414.3981240480. The cubic root of 865206817 is about 952.8838745441.

The spelling of 865206817 in words is "eight hundred sixty-five million, two hundred six thousand, eight hundred seventeen".