856171986672 has 40 divisors (see below), whose sum is σ = 2211844323280. Its totient is φ = 285382056960.

The previous prime is 856171986661. The next prime is 856171986689. The reversal of 856171986672 is 276689171658.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1453272 + ... + 1955592.

It is an arithmetic number, because the mean of its divisors is an integer number (55296108082).

Almost surely, 2^856171986672 is an apocalyptic number.

It is an amenable number.

856171986672 is an abundant number, since it is smaller than the sum of its proper divisors (1355672336608).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856171986672 is a wasteful number, since it uses less digits than its factorization.

856171986672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537841 (or 537835 counting only the distinct ones).

The product of its digits is 60963840, while the sum is 66.

The spelling of 856171986672 in words is "eight hundred fifty-six billion, one hundred seventy-one million, nine hundred eighty-six thousand, six hundred seventy-two".