9965258561280 has 576 divisors, whose sum is σ = 36666221985792. Its totient is φ = 2282925342720.

The previous prime is 9965258561227. The next prime is 9965258561287. The reversal of 9965258561280 is 821658525699.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9965258561287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 80574369 + ... + 80697951.

It is an arithmetic number, because the mean of its divisors is an integer number (63656635392).

Almost surely, 2^{9965258561280} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9965258561280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18333110992896).

9965258561280 is an abundant number, since it is smaller than the sum of its proper divisors (26700963424512).

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

9965258561280 is a wasteful number, since it uses less digits than its factorization.

9965258561280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123724 (or 123710 counting only the distinct ones).

The product of its (nonzero) digits is 93312000, while the sum is 66.

The spelling of 9965258561280 in words is "nine trillion, nine hundred sixty-five billion, two hundred fifty-eight million, five hundred sixty-one thousand, two hundred eighty".