9780840 has 96 divisors (see below), whose sum is σ = 32221800. Its totient is φ = 2572800.

The previous prime is 9780829. The next prime is 9780847. The reversal of 9780840 is 480879.

9780840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8054244 + 1726596 = 2838^2 + 1314^2 .

It is a super-2 number, since 2×9780840² = 191329662211200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 9780795 and 9780804.

It is not an unprimeable number, because it can be changed into a prime (9780847) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 36226 + ... + 36494.

Almost surely, 2^9780840 is an apocalyptic number.

9780840 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 9780840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16110900).

9780840 is an abundant number, since it is smaller than the sum of its proper divisors (22440960).

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

9780840 is a wasteful number, since it uses less digits than its factorization.

9780840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 380 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 9780840 is about 3127.4334525294. The cubic root of 9780840 is about 213.8579428127.

The spelling of 9780840 in words is "nine million, seven hundred eighty thousand, eight hundred forty".