9988561440 has 1536 divisors, whose sum is σ = 46332518400. Its totient is φ = 1970749440.

The previous prime is 9988561439. The next prime is 9988561441. The reversal of 9988561440 is 441658899.

It is an interprime number because it is at equal distance from previous prime (9988561439) and next prime (9988561441).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (9988561441) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 269961102 + ... + 269961138.

It is an arithmetic number, because the mean of its divisors is an integer number (30164400).

Almost surely, 2^9988561440 is an apocalyptic number.

9988561440 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 9988561440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23166259200).

9988561440 is an abundant number, since it is smaller than the sum of its proper divisors (36343956960).

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

9988561440 is a wasteful number, since it uses less digits than its factorization.

9988561440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The square root of 9988561440 is about 99942.7908355575. The cubic root of 9988561440 is about 2153.6129222753.

The spelling of 9988561440 in words is "nine billion, nine hundred eighty-eight million, five hundred sixty-one thousand, four hundred forty".