9978028865280 has 1728 divisors, whose sum is σ = 42227985623040. Its totient is φ = 2185368698880.

The previous prime is 9978028865267. The next prime is 9978028865309. The reversal of 9978028865280 is 825688208799.

It is a happy number.

9978028865280 is a `hidden beast` number, since 9 + 9 + 7 + 8 + 0 + 288 + 65 + 280 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

It is a super-2 number, since 2×9978028865280² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 9978028865199 and 9978028865208.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 38825014912 + ... + 38825015168.

It is an arithmetic number, because the mean of its divisors is an integer number (24437491680).

Almost surely, 2^{9978028865280} is an apocalyptic number.

9978028865280 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 9978028865280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21113992811520).

9978028865280 is an abundant number, since it is smaller than the sum of its proper divisors (32249956757760).

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

9978028865280 is a wasteful number, since it uses less digits than its factorization.

9978028865280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 523 (or 472 counting only the distinct ones).

The product of its (nonzero) digits is 278691840, while the sum is 72.

The spelling of 9978028865280 in words is "nine trillion, nine hundred seventy-eight billion, twenty-eight million, eight hundred sixty-five thousand, two hundred eighty".