9978678720 has 168 divisors, whose sum is σ = 34585808400. Its totient is φ = 2640568320.

The previous prime is 9978678713. The next prime is 9978678737. The reversal of 9978678720 is 278768799.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 364056 + ... + 390504.

Almost surely, 2^9978678720 is an apocalyptic number.

9978678720 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 9978678720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17292904200).

9978678720 is an abundant number, since it is smaller than the sum of its proper divisors (24607129680).

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

9978678720 is a wasteful number, since it uses less digits than its factorization.

9978678720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26603 (or 26590 counting only the distinct ones).

The product of its (nonzero) digits is 21337344, while the sum is 63.

The square root of 9978678720 is about 99893.3367147179. The cubic root of 9978678720 is about 2152.9024236771.

The spelling of 9978678720 in words is "nine billion, nine hundred seventy-eight million, six hundred seventy-eight thousand, seven hundred twenty".