9921280 has 72 divisors (see below), whose sum is σ = 24871392. Its totient is φ = 3784704.

The previous prime is 9921259. The next prime is 9921283. The reversal of 9921280 is 821299.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (9921283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29272 + ... + 29608.

It is an arithmetic number, because the mean of its divisors is an integer number (345436).

Almost surely, 2^9921280 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 9921280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12435696).

9921280 is an abundant number, since it is smaller than the sum of its proper divisors (14950112).

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

9921280 is a wasteful number, since it uses less digits than its factorization.

9921280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 9921280 is about 3149.8063432535. The cubic root of 9921280 is about 214.8766554095.

It can be divided in two parts, 9921 and 280, that added together give a palindrome (10201).

The spelling of 9921280 in words is "nine million, nine hundred twenty-one thousand, two hundred eighty".