9809840 has 40 divisors (see below), whose sum is σ = 23302080. Its totient is φ = 3838976.

The previous prime is 9809809. The next prime is 9809843. The reversal of 9809840 is 489089.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 9809794 and 9809803.

It is not an unprimeable number, because it can be changed into a prime (9809843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2456 + ... + 5064.

It is an arithmetic number, because the mean of its divisors is an integer number (582552).

Almost surely, 2^9809840 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 9809840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11651040).

9809840 is an abundant number, since it is smaller than the sum of its proper divisors (13492240).

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

9809840 is a wasteful number, since it uses less digits than its factorization.

9809840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2669 (or 2663 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 9809840 is about 3132.0664105347. The cubic root of 9809840 is about 214.0690958061.

The spelling of 9809840 in words is "nine million, eight hundred nine thousand, eight hundred forty".