9993644640 has 288 divisors, whose sum is σ = 39616589376. Its totient is φ = 2246676480.

The previous prime is 9993644621. The next prime is 9993644641. The reversal of 9993644640 is 464463999.

9993644640 is a `hidden beast` number, since 99 + 93 + 6 + 4 + 464 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9993644641) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 606754 + ... + 623006.

It is an arithmetic number, because the mean of its divisors is an integer number (137557602).

Almost surely, 2^9993644640 is an apocalyptic number.

9993644640 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 9993644640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19808294688).

9993644640 is an abundant number, since it is smaller than the sum of its proper divisors (29622944736).

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

9993644640 is a wasteful number, since it uses less digits than its factorization.

9993644640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16342 (or 16331 counting only the distinct ones).

The product of its (nonzero) digits is 5038848, while the sum is 54.

The square root of 9993644640 is about 99968.2181495699. The cubic root of 9993644640 is about 2153.9781863750.

It can be divided in two parts, 999364 and 4640, that added together give a square (1004004 = 1002²).

The spelling of 9993644640 in words is "nine billion, nine hundred ninety-three million, six hundred forty-four thousand, six hundred forty".