865120817 has 8 divisors (see below), whose sum is σ = 957855072. Its totient is φ = 774734400.

The previous prime is 865120811. The next prime is 865120819. The reversal of 865120817 is 718021568.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 865120817 - 2⁴ = 865120801 is a prime.

It is a super-3 number, since 3×865120817³ (a number of 28 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (865120811) 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 7 ways as a sum of consecutive naturals, for example, 586184 + ... + 587657.

It is an arithmetic number, because the mean of its divisors is an integer number (119731884).

Almost surely, 2^865120817 is an apocalyptic number.

It is an amenable number.

865120817 is a deficient number, since it is larger than the sum of its proper divisors (92734255).

865120817 is a wasteful number, since it uses less digits than its factorization.

865120817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173919.

The product of its (nonzero) digits is 26880, while the sum is 38.

The square root of 865120817 is about 29412.9362186097. The cubic root of 865120817 is about 952.8523018508.

The spelling of 865120817 in words is "eight hundred sixty-five million, one hundred twenty thousand, eight hundred seventeen".