856708007647 has 4 divisors (see below), whose sum is σ = 856965203416. Its totient is φ = 856450811880.

The previous prime is 856708007633. The next prime is 856708007711. The reversal of 856708007647 is 746700807658.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856708007647 is a prime.

It is a super-2 number, since 2×856708007647² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 856708007591 and 856708007600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856708007347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128592888 + ... + 128599549.

It is an arithmetic number, because the mean of its divisors is an integer number (214241300854).

Almost surely, 2^856708007647 is an apocalyptic number.

856708007647 is a deficient number, since it is larger than the sum of its proper divisors (257195769).

856708007647 is a wasteful number, since it uses less digits than its factorization.

856708007647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257195768.

The product of its (nonzero) digits is 15805440, while the sum is 58.

The spelling of 856708007647 in words is "eight hundred fifty-six billion, seven hundred eight million, seven thousand, six hundred forty-seven".