9981432864 has 288 divisors, whose sum is σ = 31529481984. Its totient is φ = 2976030720.

The previous prime is 9981432863. The next prime is 9981432869. The reversal of 9981432864 is 4682341899.

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

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 9981432864.

It is not an unprimeable number, because it can be changed into a prime (9981432863) 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, 23051592 + ... + 23052024.

It is an arithmetic number, because the mean of its divisors is an integer number (109477368).

Almost surely, 2^9981432864 is an apocalyptic number.

9981432864 is a gapful number since it is divisible by the number (94) 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 9981432864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15764740992).

9981432864 is an abundant number, since it is smaller than the sum of its proper divisors (21548049120).

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

9981432864 is a wasteful number, since it uses less digits than its factorization.

9981432864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640 (or 629 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The square root of 9981432864 is about 99907.1211876311. The cubic root of 9981432864 is about 2153.1004745424.

The spelling of 9981432864 in words is "nine billion, nine hundred eighty-one million, four hundred thirty-two thousand, eight hundred sixty-four".