9965639520 has 192 divisors, whose sum is σ = 35372090880. Its totient is φ = 2619993600.

The previous prime is 9965639473. The next prime is 9965639521. The reversal of 9965639520 is 259365699.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9965639521) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 290475 + ... + 322965.

It is an arithmetic number, because the mean of its divisors is an integer number (184229640).

Almost surely, 2^9965639520 is an apocalyptic number.

9965639520 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 9965639520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17686045440).

9965639520 is an abundant number, since it is smaller than the sum of its proper divisors (25406451360).

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

9965639520 is a wasteful number, since it uses less digits than its factorization.

9965639520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32586 (or 32572 counting only the distinct ones).

The product of its (nonzero) digits is 3936600, while the sum is 54.

The square root of 9965639520 is about 99828.0497655844. The cubic root of 9965639520 is about 2151.9642780470.

The spelling of 9965639520 in words is "nine billion, nine hundred sixty-five million, six hundred thirty-nine thousand, five hundred twenty".