9866663680 has 36 divisors (see below), whose sum is σ = 23633745912.
Its totient is φ = 3946664960.
The previous prime is 9866663659. The next prime is 9866663687. The reversal of 9866663680 is 863666689.
It is a super-3 number, since 3×98666636803 (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (9866663687) 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, 3852886 + ... + 3855445.
It is an arithmetic number, because the mean of its divisors is an integer number (656492942).
Almost surely, 29866663680 is an apocalyptic number.
It is an amenable number.
9866663680 is an abundant number, since it is smaller than the sum of its proper divisors (13767082232).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
9866663680 is an equidigital number, since it uses as much as digits as its factorization.
9866663680 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 7708352 (or 7708338 counting only the distinct ones).
The product of its (nonzero) digits is 13436928, while the sum is 58.
The square root of 9866663680 is about 99331.0811377788.
The cubic root of 9866663680 is about 2144.8163335294.
It can be divided in two parts, 986 and 6663680, that added together give a palindrome (6664666).
The spelling of 9866663680 in words is "nine billion, eight hundred sixty-six million, six hundred sixty-three thousand, six hundred eighty".