9805309920 has 288 divisors, whose sum is σ = 39475537920. Its totient is φ = 2168847360.

The previous prime is 9805309897. The next prime is 9805309933. The reversal of 9805309920 is 299035089.

9805309920 is a `hidden beast` number, since 9 + 8 + 0 + 530 + 99 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×9805309920² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 296791 + ... + 328169.

It is an arithmetic number, because the mean of its divisors is an integer number (137067840).

Almost surely, 2^9805309920 is an apocalyptic number.

9805309920 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 9805309920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19737768960).

9805309920 is an abundant number, since it is smaller than the sum of its proper divisors (29670228000).

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

9805309920 is a wasteful number, since it uses less digits than its factorization.

9805309920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31438 (or 31427 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 9805309920 is about 99021.7648802525. The cubic root of 9805309920 is about 2140.3613912043.

The spelling of 9805309920 in words is "nine billion, eight hundred five million, three hundred nine thousand, nine hundred twenty".