9900866856 has 32 divisors (see below), whose sum is σ = 25828349760. Its totient is φ = 3156797952.

The previous prime is 9900866851. The next prime is 9900866897. The reversal of 9900866856 is 6586680099.

It is a junction number, because it is equal to n+sod(n) for n = 9900866796 and 9900866805.

It is not an unprimeable number, because it can be changed into a prime (9900866851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8967625 + ... + 8968728.

It is an arithmetic number, because the mean of its divisors is an integer number (807135930).

Almost surely, 2^9900866856 is an apocalyptic number.

It is an amenable number.

9900866856 is an abundant number, since it is smaller than the sum of its proper divisors (15927482904).

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

9900866856 is a wasteful number, since it uses less digits than its factorization.

9900866856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17936385 (or 17936381 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 57.

The square root of 9900866856 is about 99503.0997306114. The cubic root of 9900866856 is about 2147.2918385194.

The spelling of 9900866856 in words is "nine billion, nine hundred million, eight hundred sixty-six thousand, eight hundred fifty-six".