843840 has 84 divisors (see below), whose sum is σ = 2912364. Its totient is φ = 224256.

The previous prime is 843833. The next prime is 843841. The reversal of 843840 is 48348.

It can be written as a sum of positive squares in 2 ways, for example, as 589824 + 254016 = 768^2 + 504^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 843840.

It is not an unprimeable number, because it can be changed into a prime (843841) by changing a digit.

843840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2734 + ... + 3026.

It is an arithmetic number, because the mean of its divisors is an integer number (34671).

2⁸⁴³⁸⁴⁰ is an apocalyptic number.

843840 is a gapful number since it is divisible by the number (80) 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 843840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1456182).

843840 is an abundant number, since it is smaller than the sum of its proper divisors (2068524).

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

843840 is a wasteful number, since it uses less digits than its factorization.

843840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 316 (or 303 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 843840 is about 918.6076420322. The cubic root of 843840 is about 94.4974384121.

The spelling of 843840 in words is "eight hundred forty-three thousand, eight hundred forty".