855865851971 has 4 divisors (see below), whose sum is σ = 921701686752. Its totient is φ = 790030017192.

The previous prime is 855865851961. The next prime is 855865852031. The reversal of 855865851971 is 179158568558.

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

It is a de Polignac number, because none of the positive numbers 2^k-855865851971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (855865851941) 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, 32917917371 + ... + 32917917396.

It is an arithmetic number, because the mean of its divisors is an integer number (230425421688).

Almost surely, 2^855865851971 is an apocalyptic number.

855865851971 is a deficient number, since it is larger than the sum of its proper divisors (65835834781).

855865851971 is a wasteful number, since it uses less digits than its factorization.

855865851971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65835834780.

The product of its digits is 120960000, while the sum is 68.

The spelling of 855865851971 in words is "eight hundred fifty-five billion, eight hundred sixty-five million, eight hundred fifty-one thousand, nine hundred seventy-one".