856487871 has 32 divisors (see below), whose sum is σ = 1378764800. Its totient is φ = 523480320.

The previous prime is 856487857. The next prime is 856487887. The reversal of 856487871 is 178784658.

It is a happy number.

856487871 is a `hidden beast` number, since 8 + 564 + 8 + 7 + 8 + 71 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-856487871 is a prime.

It is a super-2 number, since 2×856487871² = 1467142946340225282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856480871) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11026 + ... + 42831.

It is an arithmetic number, because the mean of its divisors is an integer number (43086400).

Almost surely, 2^856487871 is an apocalyptic number.

856487871 is a deficient number, since it is larger than the sum of its proper divisors (522276929).

856487871 is a wasteful number, since it uses less digits than its factorization.

856487871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53916 (or 53910 counting only the distinct ones).

The product of its digits is 3010560, while the sum is 54.

The square root of 856487871 is about 29265.8140327584. The cubic root of 856487871 is about 949.6722307856.

The spelling of 856487871 in words is "eight hundred fifty-six million, four hundred eighty-seven thousand, eight hundred seventy-one".