856487317155 has 32 divisors (see below), whose sum is σ = 1377454740480. Its totient is φ = 454439842560.

The previous prime is 856487317141. The next prime is 856487317159. The reversal of 856487317155 is 551713784658.

It is a Cunningham number, because it is equal to 925466²-1.

It is not a de Polignac number, because 856487317155 - 2⁴ = 856487317139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (856487317159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2622151 + ... + 2930639.

It is an arithmetic number, because the mean of its divisors is an integer number (43045460640).

Almost surely, 2^856487317155 is an apocalyptic number.

856487317155 is a deficient number, since it is larger than the sum of its proper divisors (520967423325).

856487317155 is a wasteful number, since it uses less digits than its factorization.

856487317155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309451.

The product of its digits is 28224000, while the sum is 60.

The spelling of 856487317155 in words is "eight hundred fifty-six billion, four hundred eighty-seven million, three hundred seventeen thousand, one hundred fifty-five".