856646171687 has 2 divisors, whose sum is σ = 856646171688. Its totient is φ = 856646171686.

The previous prime is 856646171653. The next prime is 856646171729. The reversal of 856646171687 is 786171646658.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 856646171687 - 2²⁰ = 856645123111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856646171617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428323085843 + 428323085844.

It is an arithmetic number, because the mean of its divisors is an integer number (428323085844).

Almost surely, 2^856646171687 is an apocalyptic number.

856646171687 is a deficient number, since it is larger than the sum of its proper divisors (1).

856646171687 is an equidigital number, since it uses as much as digits as its factorization.

856646171687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81285120, while the sum is 65.

The spelling of 856646171687 in words is "eight hundred fifty-six billion, six hundred forty-six million, one hundred seventy-one thousand, six hundred eighty-seven".