843640 has 64 divisors (see below), whose sum is σ = 2280960. Its totient is φ = 274560.

The previous prime is 843629. The next prime is 843643. The reversal of 843640 is 46348.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (843643) 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 15 ways as a sum of consecutive naturals, for example, 6375 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (35640).

2⁸⁴³⁶⁴⁰ 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 843640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1140480).

843640 is an abundant number, since it is smaller than the sum of its proper divisors (1437320).

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

843640 is a wasteful number, since it uses less digits than its factorization.

843640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 843640 is about 918.4987751761. The cubic root of 843640 is about 94.4899721543.

Adding to 843640 its reverse (46348), we get a palindrome (889988).

The spelling of 843640 in words is "eight hundred forty-three thousand, six hundred forty".