9781257289320 has 384 divisors, whose sum is σ = 35007448320000. Its totient is φ = 2348861898240.

The previous prime is 9781257289289. The next prime is 9781257289367. The reversal of 9781257289320 is 239827521879.

9781257289320 is a `hidden beast` number, since 9 + 7 + 8 + 1 + 25 + 7 + 289 + 320 = 666.

9781257289320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 178857741 + ... + 178912419.

It is an arithmetic number, because the mean of its divisors is an integer number (91165230000).

Almost surely, 2^{9781257289320} is an apocalyptic number.

9781257289320 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 9781257289320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17503724160000).

9781257289320 is an abundant number, since it is smaller than the sum of its proper divisors (25226191030680).

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

9781257289320 is a wasteful number, since it uses less digits than its factorization.

9781257289320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55133 (or 55126 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 63.

The spelling of 9781257289320 in words is "nine trillion, seven hundred eighty-one billion, two hundred fifty-seven million, two hundred eighty-nine thousand, three hundred twenty".