9866394720 has 1152 divisors, whose sum is σ = 45332711424. Its totient is φ = 1895104512.

The previous prime is 9866394701. The next prime is 9866394721. The reversal of 9866394720 is 274936689.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9866394721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 95790189 + ... + 95790291.

It is an arithmetic number, because the mean of its divisors is an integer number (39351312).

Almost surely, 2^9866394720 is an apocalyptic number.

9866394720 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9866394720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22666355712).

9866394720 is an abundant number, since it is smaller than the sum of its proper divisors (35466316704).

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

9866394720 is a wasteful number, since it uses less digits than its factorization.

9866394720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 54.

The square root of 9866394720 is about 99329.7272723529. The cubic root of 9866394720 is about 2144.7968445018.

The spelling of 9866394720 in words is "nine billion, eight hundred sixty-six million, three hundred ninety-four thousand, seven hundred twenty".