856318817 has 4 divisors (see below), whose sum is σ = 856441776. Its totient is φ = 856195860.

The previous prime is 856318811. The next prime is 856318829. The reversal of 856318817 is 718813658.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 718813658 = 2 ⋅359406829.

It is a cyclic number.

It is not a de Polignac number, because 856318817 - 2¹⁰ = 856317793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (856318811) 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 3 ways as a sum of consecutive naturals, for example, 50363 + ... + 65184.

It is an arithmetic number, because the mean of its divisors is an integer number (214110444).

Almost surely, 2^856318817 is an apocalyptic number.

It is an amenable number.

856318817 is a deficient number, since it is larger than the sum of its proper divisors (122959).

856318817 is a wasteful number, since it uses less digits than its factorization.

856318817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122958.

The product of its digits is 322560, while the sum is 47.

The square root of 856318817 is about 29262.9256397921. The cubic root of 856318817 is about 949.6097444159.

The spelling of 856318817 in words is "eight hundred fifty-six million, three hundred eighteen thousand, eight hundred seventeen".