7845840 has 120 divisors (see below), whose sum is σ = 27942408. Its totient is φ = 1966080.

The previous prime is 7845839. The next prime is 7845889. The reversal of 7845840 is 485487.

7845840 is a `hidden beast` number, since 78 + 4 + 584 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3283344 + 4562496 = 1812^2 + 2136^2 .

It is a tau number, because it is divible by the number of its divisors (120).

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 = 7845795 and 7845804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11920 + ... + 12560.

Almost surely, 2^7845840 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 7845840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13971204).

7845840 is an abundant number, since it is smaller than the sum of its proper divisors (20096568).

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

7845840 is a wasteful number, since it uses less digits than its factorization.

7845840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 36.

The square root of 7845840 is about 2801.0426630096. The cubic root of 7845840 is about 198.7069919994.

The spelling of 7845840 in words is "seven million, eight hundred forty-five thousand, eight hundred forty".