9979840 has 56 divisors (see below), whose sum is σ = 25603200. Its totient is φ = 3683328.

The previous prime is 9979819. The next prime is 9979843. The reversal of 9979840 is 489799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9979843) 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, 2961 + ... + 5359.

It is an arithmetic number, because the mean of its divisors is an integer number (457200).

Almost surely, 2^9979840 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 9979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12801600).

9979840 is an abundant number, since it is smaller than the sum of its proper divisors (15623360).

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

9979840 is a wasteful number, since it uses less digits than its factorization.

9979840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2429 (or 2419 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 46.

The square root of 9979840 is about 3159.0884761273. The cubic root of 9979840 is about 215.2985935921.

The spelling of 9979840 in words is "nine million, nine hundred seventy-nine thousand, eight hundred forty".