2805840 has 100 divisors (see below), whose sum is σ = 9767604. Its totient is φ = 746496.

The previous prime is 2805827. The next prime is 2805851. The reversal of 2805840 is 485082.

2805840 is a `hidden beast` number, since 2 + 80 + 584 + 0 = 666.

2805840 is digitally balanced in base 5, 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 2 ways, for example, as 627264 + 2178576 = 792^2 + 1476^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6264 + ... + 6696.

2^2805840 is an apocalyptic number.

2805840 is a gapful number since it is divisible by the number (20) 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 2805840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4883802).

2805840 is an abundant number, since it is smaller than the sum of its proper divisors (6961764).

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

2805840 is a wasteful number, since it uses less digits than its factorization.

2805840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 443 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 2805840 is about 1675.0641778750. The cubic root of 2805840 is about 141.0438976040.

The spelling of 2805840 in words is "two million, eight hundred five thousand, eight hundred forty".