8721806856 has 64 divisors (see below), whose sum is σ = 24945070080. Its totient is φ = 2489382720.

The previous prime is 8721806827. The next prime is 8721806861. The reversal of 8721806856 is 6586081278.

It is a junction number, because it is equal to n+sod(n) for n = 8721806799 and 8721806808.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140295 + ... + 192681.

It is an arithmetic number, because the mean of its divisors is an integer number (389766720).

Almost surely, 2^8721806856 is an apocalyptic number.

It is an amenable number.

8721806856 is an abundant number, since it is smaller than the sum of its proper divisors (16223263224).

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

8721806856 is a wasteful number, since it uses less digits than its factorization.

8721806856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53394 (or 53390 counting only the distinct ones).

The product of its (nonzero) digits is 1290240, while the sum is 51.

The square root of 8721806856 is about 93390.6143892415. The cubic root of 8721806856 is about 2058.4270878693.

The spelling of 8721806856 in words is "eight billion, seven hundred twenty-one million, eight hundred six thousand, eight hundred fifty-six".