9921648844800 has 2016 divisors, whose sum is σ = 45179081925120. Its totient is φ = 2021208883200.

The previous prime is 9921648844781. The next prime is 9921648844817. The reversal of 9921648844800 is 84488461299.

9921648844800 is a `hidden beast` number, since 9 + 92 + 1 + 64 + 8 + 8 + 4 + 480 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (2016).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 7522098541 + ... + 7522099859.

Almost surely, 2^{9921648844800} is an apocalyptic number.

9921648844800 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 9921648844800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22589540962560).

9921648844800 is an abundant number, since it is smaller than the sum of its proper divisors (35257433080320).

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

9921648844800 is a wasteful number, since it uses less digits than its factorization.

9921648844800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432 (or 1400 counting only the distinct ones).

The product of its (nonzero) digits is 31850496, while the sum is 63.

It can be divided in two parts, 99216 and 48844800, that added together give a square (48944016 = 6996²).

The spelling of 9921648844800 in words is "nine trillion, nine hundred twenty-one billion, six hundred forty-eight million, eight hundred forty-four thousand, eight hundred".