2781856 has 48 divisors (see below), whose sum is σ = 6834240. Its totient is φ = 1082880.

The previous prime is 2781853. The next prime is 2781887. The reversal of 2781856 is 6581872.

It is an Ulam number.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (2781853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1900 + ... + 3028.

It is an arithmetic number, because the mean of its divisors is an integer number (142380).

2^2781856 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 2781856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3417120).

2781856 is an abundant number, since it is smaller than the sum of its proper divisors (4052384).

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

2781856 is a wasteful number, since it uses less digits than its factorization.

2781856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157 (or 1149 counting only the distinct ones).

The product of its digits is 26880, while the sum is 37.

The square root of 2781856 is about 1667.8896846015. The cubic root of 2781856 is about 140.6408713609.

The spelling of 2781856 in words is "two million, seven hundred eighty-one thousand, eight hundred fifty-six".