845840 has 40 divisors (see below), whose sum is σ = 2005080. Its totient is φ = 331776.

The previous prime is 845833. The next prime is 845849. The reversal of 845840 is 48548.

It can be written as a sum of positive squares in 4 ways, for example, as 126736 + 719104 = 356^2 + 848^2 .

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

It is not an unprimeable number, because it can be changed into a prime (845849) by changing a digit.

845840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7706 + ... + 7814.

It is an arithmetic number, because the mean of its divisors is an integer number (50127).

2⁸⁴⁵⁸⁴⁰ is an apocalyptic number.

845840 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 845840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1002540).

845840 is an abundant number, since it is smaller than the sum of its proper divisors (1159240).

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

845840 is a wasteful number, since it uses less digits than its factorization.

845840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 29.

The square root of 845840 is about 919.6956018162. The cubic root of 845840 is about 94.5720361873.

The spelling of 845840 in words is "eight hundred forty-five thousand, eight hundred forty".