9921828 has 48 divisors (see below), whose sum is σ = 27377280. Its totient is φ = 2736384.

The previous prime is 9921827. The next prime is 9921851. The reversal of 9921828 is 8281299.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (9921823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 400 + ... + 4472.

It is an arithmetic number, because the mean of its divisors is an integer number (570360).

Almost surely, 2^9921828 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 9921828, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13688640).

9921828 is an abundant number, since it is smaller than the sum of its proper divisors (17455452).

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

9921828 is a wasteful number, since it uses less digits than its factorization.

9921828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4116 (or 4114 counting only the distinct ones).

The product of its digits is 20736, while the sum is 39.

The square root of 9921828 is about 3149.8933315273. The cubic root of 9921828 is about 214.8806115603.

The spelling of 9921828 in words is "nine million, nine hundred twenty-one thousand, eight hundred twenty-eight".